For better fuel economy and allaround performance driving, most Restomod guys swap in late-model transmissions with extra gears or overdrives. This section will cover the most popular manual and automatic transmission swapping info, where to get the parts, and what is offered by each manufacturer. Selecting a transmission to run in your car is determined by a few factors, including but not limited to: your everyday driving style, frequency, and distance; the condition of your clutch knee; whether or not you want to cut a hole in your floorpan; whether you drag race, road race, or both; and the size of your wallet. If you decide on a stick shift, do you want the smoother shift of an internal-rail shifted Tremec TKO or T-56? Would you rather have more gear ratio selections like a Richmond 6- speed? If you pick an automatic overdrive, do you want it to be manually controlled like the Ford AOD, or do you want to fork out the extra dough for the computer controller so you can use a 4R70W transmission? New transmissions might come out that will work even better for you. Maybe Ford will come out with newer and stronger transmissions, like a 7-speed manual, or maybe a 6-speed automatic.
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This section is devoted to technical information about a couple of companies offering Tremec TKOs and T-56 variants, Richmond 6-speed transmissions, and conversion kits. There are a lot of companies offering conversion parts and some incomplete kits, so space limits the company coverage to a select few.
If you want to drop a bunch of extra money for transmissions that will hold the loads a standard production transmission won’t, you can check offerings from G-Force Transmissions, Tex Racing, or Quaife. For instance, the standard production Borg Warner T-5 is rated to a capacity of 300 ft-lbs, while the reworked G-Force T-5 is rated at 500. Depending on the model of the production T-56, it can be rated as high as 550-ft-lbs, and the reworked G-Force T- 56 handles around 800. Tex Racing Enterprises offers racing 4-speed transmissions with a Chevrolet mounting pattern (an adapter bellhousing is required) for Extreme Restomods built mostly for track racing. Quaife makes outrageous racing drivetrain parts for racing cars, with prices to match the level of performance and quality. The old adage “You get what you pay for.” applies to these companies. These transmissions may be a cut above an average Restomod unit, but if you’re making that kind of power, you’ll end up needing one sooner or later.
If you want 5 gears, don’t have excessive amounts of power, and don’t want to modify the transmission tunnel, get yourself a Borg Warner T-5. You should be aware that the production T- 5s come in different flavors and ratings from 230 to 330 ft-lbs of torque. When swapping a T-5 into a small-block Ford Restomod, for best results, you should get a T-5 from a V-8-powered 1990 to 1993 Mustang.
For those of you putting a latemodel 5.0-liter engine in an early car equipped with mechanical Z-bar clutch linkage, you will run into problems.
The later model blocks don’t have the boss on the side of the block for the Zbar linkage stud. You can make your own, or purchase an adapter bracket from Kaufmann Products and Total Performance.
Tremec TKO 5-speed
Swapping in any of the TKO 5- speeds into an early shock-tower car is tricky. There is a lot of different information available on what cars the TKO fits in, with and without modifying the transmission tunnel. The TKO has two large high-mounted inspection covers and the shifter. These covers are tall enough that they can hit the underside of the transmission tunnel when you install the transmission and engine with the correct pinion angle (as seen in the pinion-angle diagram in Chapter 3). For Falcons and 1964-1⁄2 to 1970 Mustangs, the transmission tunnel needs to be raised about 1 inch to clear the top of the TKO. There are companies selling transmission crossmembers that allow you to install the TKO in these early Mustangs without modifying the transmission tunnel. They say, “It only gives you an extra 3 degrees down on the transmission, but that’s not a problem.” There is a problem with this logic. The transmission is originally 3 degrees down, so when you add 3 more degrees, it adds up to a total of 6 degrees down. This angle can spell problems for your U-joints. Add a bunch of extra stress from increased horsepower and torque, and it will spell trouble. You may get lucky and never have a failure, but your chances are greatly increased. Shops that have a serious understanding of pinion and driveshaft angles would not cut corners. These shops would install the transmission at the correct angle and modify your transmission tunnel if necessary. If you want to purchase one of these “pinion-angle-challenged” crossmembers and install shims between the crossmember and trans mount to raise it to get the correct angle, you would at least save some time fabricating the entire unit. Then you just need to modify the trans tunnel since you raised the transmission to the proper height. For the various other Restomod candidates out there, the best way to see what will fit is to start measuring.
Keisler Automotive Engineering
The people over at Keisler Automotive Engineering do all the homework for you. They offer kits for Ford Restomods, as well as Chevrolet and Mopar muscle cars. The TKO 500 and 600 offered by Keisler Automotive Engineering have a few different shifter locations (not including the different locations available straight from Tremec), so depending on your application, you may be able to use the stock shifter location and keep your factory console. Keisler takes pride in making its kits correct and complete. When I say “correct,” I mean that the kits are designed to allow for the correct pinion angles. To achieve the correct angle, it may be necessary to modify the transmission tunnel. If it is, Keisler includes the templates for cutting and the necessary sheetmetal cover to finish the job like a professional. The bolt-in kit includes all the parts necessary to bolt everything in, including the driveshaft for your specific application, wiring, and the crossmember. Keisler is constantly adding new kits, so if you go to the website and don’t see your application, make a call and check, just to be sure.
The most popular 6-speed manual transmission (production or aftermarket) from the late 1990s to present is the Tremec T-56 (formerly BorgWarner T- 56). Tremec saw a market for offering T- 56s for Fords and an aftermarket T-56 (Tremec part # 1386-000-012) to fit smallblock Fords. The resulting transmissions have been a huge help for Restomodders looking for a sixth gear. The additional overdrive in the T-56 allows for better fuel economy and higher top speeds. Tremec’s aftermarket T-56 fits the 1965 to 1993 289, 302 (and 5.0), and 351C/W with a 6-bolt transmission mounting face. The T-56 does not fit the Modified smallblocks or any of the big-blocks. If you want a T-56 to fit a Modular engine, that’s easy, since Ford started offering it in the production 2003 and 2004 Cobra The Tremec T-56 is rated at 450 ftlbs of torque. It requires a cable-operated clutch set-up and it is longer than any other manual transmission in overall length, so a shorter driveshaft will be needed. The transmission mount is also further back than any other Ford transmission mount, so you’ll need to modify the crossmember or get a new one. It shares the 10-spline Ford-style input shaft with the T5. The output shaft is a 31-spline unit, so unless you are upgrading from a T5, you will need a new transmission yoke.
The following is a list of 4-speeds for comparison against the T-56:
1966 4-speed Ford Syncromesh BorgWarner T-10
Gear Ratios: First 2.36:1, Second 1.62:1, Third 1.20:1, and Fourth 1.00:1
1964-1973 4-speed Ford Top Loader – close ratio
Gear Ratios: First 2.32:1, Second 1.69:1, Third 1.29:1, and Fourth 1.00:1
1964-1973 4-speed Ford Top Loader – wide ratio
Gear Ratios: First 2.78:1, Second 1.93:1, Third 1.36:1, and Fourth 1.00:1
Tremec Aftermarket T-56 for Fords
Gear Ratios: First 2.97:1, Second 2.07:1, Third 1.43:1, Fourth 1.00:1, Fifth 0.80:1, Sixth 0.62:1, Reverse 3.28:1 Design Torque Rating: 450 ft-lbs
Keisler Automotive Engineering
The T-56 offered by Keisler Automotive Engineering has a few different shifter locations, so depending on your application, you may be able to use the stock shifter location and your factory console. Keisler manufactures a unique shifter mounting location for the T-56, which allows it to be used with street rods, trucks, and cars with bench seats. This is a typical shortcoming of the T-56, but Keisler’s custom T-56 eliminates this problem completely. Keisler offers bolt-in kits that include all the parts necessary to bolt everything in, including the driveshaft for your specific application, wiring, and the crossmember. Even if the guys at Keisler don’t have a kit for your specific application, they may be able piece together a kit from the parts they already have in stock.
The D&D Performance T-56 starts life as a Viper model transmission, rated at 550 ft-lbs of torque. To get that increased strength, the Viper T-56 has a larger input and output shaft than the Tremec aftermarket unit. While D&D has the transmission taken apart for blueprinting, it also gets upgraded shift forks and rings as well as some other modifications performed by D&D. D&D installs a custom mid-plate (front cover for end-loading), an output shaft modified to accept a mechanical geardriven speedometer, and tailshaft housing modified to house the speedometer gear assembly. These upgraded units fit the same small-block applications as the Tremec aftermarket unit, and D&D offers them for bolting behind the Modular engines as well. The large 30-spline Viper output shaft requires a Viper driveshaft yoke.
D&D Viper conversion
T-56 Gear Ratios: First 2.66:1, Second 1.78:1, Third 1.30:1, Fourth 1.00:1, Fifth 0.74:1, Sixth 0.50:1, Reverse 3.28:1 Design Torque Rating: 550 ft-lbs
You’ll need a speedometer to know how fast you’re going. There are two types of speedometers: electronic and mechanical. Some modified T-56s are offered with a mechanical speedometer. Most factory (GM and Viper) T-56 transmissions are equipped with an electronic speedometer that reads a signal from the reluctor ring on the output shaft in the tail-shaft housing. To pick up this signal, you have to get a factory vehicle speed sensor (VSS) that attaches to the transmission. There are aftermarket speedometers that read this signal and convert it to operate the indicator needle. If you want to keep the stock mechanical speedo or use an aftermarket mechanical unit, but don’t have a mechanical speedocable receiver on the tail-shaft housing, you’re in luck. There is a little black box on the market that converts the pulse signal to an electric drive motor that accepts the mechanical speedo cable. By moving some simple dip switches, you can program the output for different rear-end gear ratios and tire diameters.
If you’d rather have a mechanical speedo gear straight out of the transmission, you can pick up a modified tailshaft housing from Jags That Run (JTR). They also offer services to put in a mechanical speedometer, relocate the VSS, and install a reluctor ring. Having both a mechanical speedometer and a VSS would be necessary if you have a mechanical speedometer and a computer-controlled fuel-injection system that requires a VSS signal to operate.
Richmond Performance Products
Richmond Performance Products offers ring-and-pinion gears and transmissions. The line includes 2-speeds, 4- speeds, 5-speeds (street and road-race versions), and 6-speeds. Since I can’t remember the last time I saw someone swapping in a Richmond 5-speed, I’ll focus on the 6-speed.
The Richmond 6-speed (aka ROD – Richmond OverDrive) is put together using NASCAR-proven technology. Its shifter has external arms and side levers. The transmission mount is located approximately 5 inches rearward of the standard top-loader 4-speed, so the crossmember will have to be modified. The centerline of the shifter location is closer to the position of 4-speed shifters than the Tremec aftermarket T-56. You’ll also have to modify the transmission tunnel for the shifter location. The ROD overall length is within a 1⁄2-inch of the T-10 and top loader. It is not as large as the T-56 in overall case diameter, which makes it easier to swap without modifying the tunnel.
Richmond 6-speeds are available with two different drive ratios, along with multiple gear ratios.
1.682:1 Drive Ratio
First 4.41:1 thru 3.04:1, Second and Third 2.75:1 thru 1.57:1, Fourth 1.24:1 and 1.74, Fifth 1.00:1, Sixth .76:1 thru .91:1
1.148:1 Drive Ratio
First 3.01:1 thru 2.08:1, Second and Third 1.88:1 thru 1.07:1, Fourth .84:1 and 1.19:1, Fifth 1.00:1, Sixth .52:1 thru .62:1
PRESTON PETERSON’S 1967 MUSTANG
When you look up the word “extreme” in the dictionary, you will find that it means (A) existing in a very high degree, (B) going to great or exaggerated lengths, or (C) exceeding the ordinary, usual, or expected. All three definitions fit when you try to describe Preston Peterson’s 1967 Mustang. Usually you can put cars in the extreme Restomod or Pro-Touring category if a car is equipped with a fully fabricated tubular chassis. Preston has taken the term to an entirely new level. From a distance, you see an extremely low Mustang with big flares attached to the fenders. These types of flares can be found on European racing cars, such as entries in the Deutsche Tourenwagen Meisterschaft or DTM racing series. The 1967 was wider than the previous 1966 body, but it wasn’t wide enough for what Preston wanted to do with the car. He already had a full set of Shelby flares, but they were not extreme enough.
What you don’t see from a distance is that under the flares and stock sheet metal is a full-tilt racecar. The body panels were cut off the original chassis. This car has been in more pieces than a 1/25-scale model car. The body sections were the roof, the quarter panels, the tail panel, doors, and the front sheet metal. The original unibody underbody was discarded. This was so he could start from scratch and fit the 18-inch CCW wheels. Yes, the car was built to fit the wheel package.
The frame design is mostly based on late-model Trans-Am series cars. The frame is underslung in the front and rear, and it doesn’t kick up on either end for suspension. The rear axle has frame rails under and over the top. The design was analyzed with Grape, a Finite Element Analysis (FEA) shareware program he received from RaceCar Engineering magazine, using a torsional analysis spreadsheet. Preston picked tubing size, wall thickness, and design from his extensive chassis research of Trans-Am, NASCAR, drag race, and street-rod frame construction and SCCA rules. Once he finished construction of the frame, he started fitting body panels on the chassis so he could build the rest of the car to fit under the skin. Every part of the car was engineered to the gills. For example, the exhaust is routed up into the quarter panel where the Dynomax SuperTurbo mufflers are tucked away for the ultimate ground clearance. Up front, he built a custom set of headers with 34- inch long 1.75-inch primaries and 3-inch collectors.
Preston wants to thank C&D Machine in Kirkland, California, for build ng the 396-ci stroker using a Ford Motorsports A351 block that has been modified to hold four-bolt main caps and Scat 3.85-inch forged stroker crankshaft with Eagle H-beam rods spinning on Chevrolet rods journals. Slugs are forged Probe 0.040s with a 27-cc dish. The air-and-fuel mixture is pressurized to 13 psi by a Novi 2000 Race supercharger, and cooled by a ProCharger 3- core intercooler. The Carb Shop built the blow-through 750-cfm carburetor, which sits atop an Edelbrock Victor, Jr. and AFR 205 heads with a C&D Machine valve job. Preston installed a Probe stud girdle to keep the FlowTech Induction hydraulic roller 232/240- degree, 0.566/0.555-inch-lift camshaft in check. Fuel is supplied by a Product Engineering Sportsman 310 pump and an Aeromotive bypass regulator. Fire is supplied by an MSD boost retard and Crane Hi-6 box. Other electric accessories include an FJO wideband oxygen sensor and MSD knock sensor. The pressurized package is kept cool by a Weiand water pump and a custom Howe Racing radiator with internal oil cooler, using a Lincoln Mark VIII fan to keep excessive amounts of air flowing. To keep the stroker fully lubricated while keeping the engine placed low in the chassis, he installed a Weaver dry-sump system with the tank in the trunk. Gears are selected by a Tremec 5-speed, while the McLeod 10.5-inch dual-disc Street Twin and 157-tooth aluminum flywheel keeps everything engaged and able to spin quickly. The complete package hammered the dyno with 791 hp at 5,800 rpm with 13 psi.
In extreme fashion, Preston made the upper and lower control arms from Coleman Racing stock car parts, which swing a custom set of Coleman spindles. Steering is accomplished by a KRC pump and a BRT rack and pinion. Combined with the 285/30-18 Michelin Pilots and CCW 18×10-inch wheels with 9 inches of backspacing, it only has a 0.5-inch scrub radius. A Speedway 1.25-inch 0.180 wall tubular sway bar keeps sway under control. Neatly tucked in the rear of the chassis are a Coleman full-floater 9-inch rear end with 0.5-degree negative camber, 3.55:1 gears, Auburn limited-slip differential, and a differential cooler. The 3-link suspension is made from a Hoerr racing panhard bar and Coleman links. The front and rear corners are dampened by AFCO double adjustable coil-over shocks. Sticking to the ground in the rear is a pair of Michelin Pilot 335/30-18 tires coupled with CCW 18×13-inch wheels with 7 inches of backspace. Braking is handled by Sierra Grand National billet calipers and 13-inch Coleman rotors and hats in the front and PBR calipers on 13-inch rotors in the rear.
After building the entire chassis, Preston attached all the body panels to it. Then he built the flares from scratch and installed ducting around the radiator, positioned so air could flow through the radiator and exit through the top of the hood, instead of pressurizing the engine compartment. Once all the custom work was done, he had Jim Maesner cover the external surfaces with a medium blue. Then it was time for Preston to turn the interior of this racecar into something that looked and felt more like a street car, since he plans to put about 7,000 miles on the car annually. He installed Kirkey Road Race Deluxe seats, Simpson harnesses, a Grant steering wheel, and AutoMeter and VDO gauges. For creature comforts, he added a Kenwood stereo system and power locks/windows.
If it wasn’t extreme enough, he has decided that he wants a twin turbo setup, upgraded to the latest Tremec TKO offering. He also wants to install a new gear set, make some more modifications to the front suspension, and install bigger brakes. If you were writing a car dictionary, you may find a picture of Preston’s 1967 Mustang to help demonstrate what the word “extreme” means.
When bolting on any stock or aftermarket bellhousing with a centering hole that locates the transmission front-bearing retainer, you need to check some critical measurements. If you just bolt one on your car and throw in a transmission, you run a high probability of destroying your pilot bearing, input shaft bearing, input shaft, and other internal parts. The symptoms can be extreme clutch chatter, engagement problems, and erratic clutch operation. Aftermarket companies typically have a maximum specified run-out of .010 inch. Check with the manufacturer of your bellhousing for exact measurements and instructions. There are two bellhousing alignments to check. First, check the run-out on the inside circumference of the pilot hole compared to concentricity of the crankshaft centerline. You do this by mounting a dial indicator on the end of a stand, with a magnetic base centered on the end of the crankshaft. Turn the crankshaft and check for a minimum of .010 inch. The second measurement to check is the mounting surface of the bellhousing. It should be within the same .010 inch from top to bottom and side to side. Mount the dial indicator to an extended arm that places it on the mounting face, and then turn the crankshaft. If you have anything over the .010-inch measurement on either location, then you will need to adjust the bellhousing with offset dowel pins or other methods suggested by the manufacturer.
McLeod Industries is one of the major companies in the clutch, flywheel, and bellhousing industry.
Industries offers street and racing clutches in both single- and dual-disc set-ups. It also offers multidisc clutches for serious racing applications. One of McLeod’s most popular heavy-duty clutches for Restomods is the Street Twin clutch set-up. It’s available with a steel or a lightweight aluminum flywheel. If you want a clutch that’s bulletproof, you can get the oval-track, road-race, or dry-lakes clutches. The non-strapped single clutch set-up holds up to 500 ftlbs of torque, and the dual-disc model holds up to 900 ft-lbs of torque. If you are serious about your power, you can step up to the triple-disc set-up, which is rated at 1,500 ft-lbs. McLeod also offers these road-race clutches in a strapped version to limit the chatter. The strapped single- and dual-disk setups have the same torque capacity ratings as the non-strapped models, but McLeod doesn’t offer a strapped triple disc set-up. The strapped clutches are only available with a lightweight aluminum flywheel.
Bellhousings and Adapters
McLeod makes heavy-duty bellhousings for just about any make and model. For those of you wishing to bolt a T-56 or other Ford, Chevy, or Chrysler manual transmission to your Ford engine, McLeod has come out with the ultimate in bellhousing. It’s a Modular, heavy-duty, multi-pattern bellhousing that bolts to most Ford small-block and big-block engines from 1962 on up, including the straight-6, Modular V-8, and V-10 patterns. It also features starter pockets on both sides of the block. Since each transmission has a different length of input shaft, there are adapter rings to space out the transmission-mounting surface. The spacer rings are available in five different thicknesses, ranging from .25 to 1.9 inches.
Tilton Engineering has a full line of performance clutches, flywheels, and other racing components. If you’re racing your Restomod more than you are driving it on the street, you can upgrade to a Tilton Driveline Components OE-diameter flywheel for use with a 7.25-inch-diameter multiple clutch and pressure plate set-up. This set-up reduces reciprocating and overall weight, while allowing you to use a standard bellhousing bellhousing.
If you are building an Extreme Restomod and want a few extra inches of ground clearance, Tilton Driveline Components has what you need. The Ultimate Low Ground Clearance Driveline Packages replace your standard bellhousing, clutch, pressure plate, throw-out bearing, and starter. The new package has an 8.64-inch-diameter flywheel (compared to the 13.25-inch small-block Ford unit), heavy-duty clutch, custom hydraulic release bearing, special starter, and low-profile custom bellhousing available in steel or magnesium. This kit gives an additional 2.25 inches of ground clearance, while reducing the reciprocating and overall weight.
There are a few good automatics on the market. I’ll be paying special attention to overdrive transmissions in this section, since Restomodding is about driving hard while keeping an eye on street driveability. There are many companies with overdrive transmissions and swap kits. I prefer the products from Windsor Fox Performance Engineering and Baumann Engineering/Baumann Electronic Controls.
In general, when converting from a C4 to an AOD or AOD-E/4R70W, you’ll need to install a new block plate designed for the overdrive transmission before installing the flex plate and converter. The C4 block plate will not allow you to mount the starter properly. The C4 dipstick tube won’t work either, so make sure you have a new dipstick and tube for the overdrive transmission. Swapping the flexplate is also necessary; however, different engines require different flexplates with different weight. The transmission mount is in a different location, so a custom crossmember is necessary. The overdrive swaps are common, so many companies offer bolt-in crossmembers.
The overdrive transmissions are wider than C4 automatic transmissions, so exhaust pipe and header interference is a common problem. Overdrive transmissions are close to the same case size as the C6, so swapping from a C6 should not pose space constraint problems. If you have full-length headers in your C4- equipped car before the swap, there’s a good chance they’ll have to be modified. Not many header manufacturers build full-length headers with overdrive transmission size in mind. Ford Powertrain Applications makes headers for some applications with the wider overdrive transmissions.
The AOD transmission is a good way to get more drivability out of your Restomod. The overdrive gear allows you to run a lower RPM at freeway speeds for better fuel mileage. The AOD is a less-expensive overdrive upgrade than the AOD-E/4R70W, due to its manually operated TV (throttle valve) cable. The AOD-E/4R70W requires a more expensive computer controller for line pressure and downshifting. With the AOD, downshifting is controlled via a TV cable attached from the transmission to the throttle linkage. The AOD transmissions that work with a TV cable were built from 1986 to 1993. Earlier models had rod-style linkage and are not desirable, unless converted to use a TV cable, which is not easy.
With an AOD, TV cable adjustment is critical. If you don’t have it connected and adjusted right, you can destroy your transmission in a matter of minutes. If your TV cable is out of adjustment, your transmission will not shift into gear, or the shift will be sluggish, instead of firm. There are a couple different types of TV cables: the block type and the lift-tab type. Typically, if you purchased an AOD transmission from a company that knows you’re doing a swap, instructions will be included for adjusting the type of cable installed on your transmission. Some Restomodders have found great success with the aftermarket TV cable assembly from Lokar Performance Products. Some Lincoln AOD transmissions have a specific driveshaft yoke that is no longer in production, so if you pick up a Lincoln unit, make sure you get the output shaft yoke or entire driveshaft out of the same donor car.
AOD Gear Ratios:
First 2.40:1, Second 1.47:1, Third 1.00:1, Fourth .67:1 Horsepower capacity (stock): up to 350 hp Horsepower capacity (modified): up to 500 hp* Overall length: 303 ⁄8 inches Case front to transmission mount distance: 225 ⁄16 inches.
The 4R70W (also known as the AOD-EW) is basically an AOD-E with a wide ratio gear set. Both transmissions are electronically controlled. Running one in your non-computer-controlled Restomod will require you to use an electronic transmission controller, available from companies like Baumann Engineering and TCI Automotive. The controller allows you to use a laptop computer to program shift points, line pressure, and torque-converter clutch operation for the best drivability with your engine set-up and the type of driving you want to do. The electronic controller is the expensive part of upgrading to one of these transmissions. These two transmissions are inherently stronger than the AOD, and worth the added expense if you have a high-output powerplant.
AOD-E Gear Ratios:
First 2.40:1, Second 1.47:1, Third 1.00:1, Fourth .67:1 Horsepower capacity (stock): up to 400 hp Horsepower capacity (modified): up to 600 hp* Overall length: 313 ⁄16 inches Case front to transmission mount distance: 235 ⁄16 inches.
4R70W Gear Ratios:
First 2.84:1, Second 1.55:1, Third 1.00:1, Fourth .70:1 Horsepower capacity (stock): up to 400 hp Horsepower capacity (modified): up to 600 hp* Overall length: 313 ⁄16 inches Case front to transmission mount distance: 235 ⁄16 inches.
The E4OD is known as a large transmission made for heavy trucks. It can be hard to fit the E4OD into the smaller transmission tunnels found in cars, which means you’ll probably have to modify the tunnel to some degree. However, if you have a 385-series big-block and want to run an automatic overdrive transmission, this is currently your only choice. The E4OD isn’t known as a brutally strong transmission in its original form, but the aftermarket has proven to increase its power capacity. Installing an E4OD in your car will be a chore since companies are not producing installation kits for these transmissions. Yet, the hard work will pay off for big-block owners.
Like the AOD-E and 4R70W transmissions, the E4OD is electronically controlled. Running one in your noncomputer-controlled Restomod will require you to use an electronic transmission controller, available from companies like Baumann Engineering and TCI Automotive. The controller allows you to use a laptop computer to program shift points, line pressure, and torque converter clutch operation for the best drivability with your engine setup and the type of driving you want to do. The electronic controller is the expensive part of upgrading to one of these transmissions.
E4OD Gear Ratios:
First 2.72:1, Second 1.53:1, Third 1.00:1, Fourth .71:1 Horsepower capacity (stock): up to 400 hp
Horsepower capacity (modified): up to 600 hp*
Overall length: 371 ⁄2 inches
Case front to transmission mount distance: 293 ⁄8 inches
*NOTE: These horsepower capacities stated are specifications for transmissions modified by Baumann Engin eering. The numbers are Bauman’s highest-rated transmissions. Other manufacturers offer similar modified transmissions.
Coolers All automatic transmissions need a transmission cooler of one form or another. Standard-duty car applications typically require a cooler at least 1.5x7x14 inches in size. If you are going to drive your Restomod like a madman or take it out on a road course on a regular basis, you should upgrade to a larger transmission cooler. The harder you drive your car, the more heat your transmission is going to produce. Each company has a little different way to check for the exact cooler size your car will need. If you contact Setrab (a company that specializes in racing coolers), they will ask you some specific details about your application and suggest a cooler that will best fit your needs. For more information on cooler types and mounting them, you should check the “Power Steering Coolers” section in Chapter 2.
Ford 8- and 9-inch rear ends consist of a welded stamped-steel housing. The 9-inch is much stronger than the 8-inch, so it’ll be the focus here. The differential and gear set are held inside a cast center section (usually referred to as a “pumpkin”) that bolts to the housing. Retaining plates on the ends of the axle housing hold the bearings, which keep the axles in their respective places.
The Ford 9-inch, besides being easy to service and work with because of its removable carrier, has more gear ratios available than any other rear end on the market. It’s also one of the strongest differentials around. The 9-inch is also more common than the 8.8, and though it is no longer produced by Ford, there are plenty in junkyards and complete center sections, gear sets, differentials, and even complete housings are available through the aftermarket. Companies like CA Chassisworks, Currie Enterprises, and Moser Engineering build complete, new, 9-inch housings that will bolt right into just about any performance car. They come in the correct width and with all the necessary mounting brackets already welded on. Currie and Moser offer housings completely assembled with third members and axles. The availability, plus the brute strength of the 9-inch, makes it the most popular choice for Restomods.
Ford’s 8.8-inch rear end is a very popular rear end found in some light trucks and V-8 Mustangs. The 8.8 features an integral carrier, which means you can’t remove just the pumpkin. This means that for gear changes, you’ll either have to drop the entire rear end, or just do it with the rear end in the car. Many people praise the 8.8 for having the strength of the 9-inch in a lighter, moreefficient design.
Having a limited-slip differential of some kind is almost a necessity for a high-performance Restomod. There are two basic types of differentials worth considering for your Restomod: limitedslip and locking. While they operate in different ways, these differentials essentially keep both axles locked together when the car is traveling in a straight line (to varying degrees). The locked axles improve traction.
Ford’s Equa-Lok and Traction-Lok are examples of limited-slip differentials. They use a system of plate-style clutches to get the power smoothly to the wheels. Limited-slip differentials do a pretty good job of locking the wheels together when the car is going straight, but they also allow the outside wheel to turn faster around corners. Think of them as a more practical, streetable alter native to a full-on locker. Most limitedslips are a perfect fit for Restomods since they need to accelerate in a straight line and around corners. New, limited slips are available for Ford rear ends from a number of aftermarket suppliers such as Richmond Gear and Auburn, which uses cone-shaped clutches. If you’re on a budget, you can also find a Ford limitedslip for your application and rebuild it.
If only the most traction available will do, you might want to step up to a locker. A locker gets its name from its ability to fully lock the wheels together when they are turning at the same speed. When a car with a locker goes around the corner, the lock has to unlock before the wheels can turn at different speeds. The transition between locked and unlocked can be a noisy little process, and may be a little unpredictable on the street or a road course. The DAPCO No-Spin, also known as the Detroit Locker, is the most notorious locker and it is available for Ford 8.8-inch and 9- inch rear ends.
The gear ratio you choose depends on a number of variables: how much torque your car’s engine produces, when your engine produces the most torque, what kind of tranny gearing you have, and how tall your tires are, and more. In general, an overdrive tranny (automatic or manual) will take a lower rear-end gear (higher ratio), from 4.10:1 to 3.70:1. This will give your car good launches, good low-end pickup, and still keep it at reasonable RPM for highway speeds.
If you’re using a 4-speed or nonOD automatic transmission with a 1:1 final drive ratio and plan on a lot of highway use, you’ll probably want a slightly higher gear (3.50:1 to 3.10:1) to keep the RPM reasonable on the road. A healthy engine with good low-end torque will still let you get off the line okay if you choose this route. On the other hand, if you plan to use the car more on the track or for local cruising, a lower gear will do the job.
Changing or installing gears in a differential is best left to a professional, unless you have the right tools and a decent understanding of the settings necessary to get the job done. The pinion depth needs to be shimmed, bearings on either end of the carrier need to be set with the correct preload, and the proper backlash must be set on the ring and pinion. Limited-slip carriers also need to have their clutches checked and serviced if necessary
Written by Tony Huntimer and Posted with Permission of CarTechBooks