There has always been some confusion when it comes to Cleveland block identification. The 351C block castings, despite different casting numbers, are all basically the same casting and can all be converted to four-bolt main caps with help from a qualified machine shop. All have the same main webs and pan rails. And if you take away the casting numbers and date codes, these blocks tend to defy detection except for minor casting changes. Any Cleveland two-bolt main block can be converted to a fourbolt main if you have the stock iron or aftermarket steel billet caps.
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Where Cleveland blocks and terminology get confusing is 351C versus 400 and 351M. Though the 400 is called the “400M” by a lot of people, it has never been called this by Ford Motor Company. The raised-deck 400 Cleveland, first introduced for model year 1971, was always known as the “400.” When Ford destroked the 400 to 351 ci and called it the 351M in 1975, people started calling the largest Cleveland the 400M. No matter how you look at the 400 or the 351M (for Modified or Midland), both use the same block casting that was in production from 1971 to 1982 though there are different part numbers. The “M” designation was conceived to differentiate the 351C from the raised-deck 351M, which replaced the 351C in 1975.
One thing that stumps Cleveland enthusiasts more than anything else are the nuances not explained in the Ford parts books. For example, did you know Ford produced 400 blocks in 1971 with small-block bellhousing bolt patterns and undrilled big-block bolt patterns (which can be drilled and tapped)? And did you also know Australian Cleveland blocks are different than their North American counterparts? Though the Cleveland V-8 is as popular in Australia as the smallblock Chevy or 5.0L Ford is here, Ford never produced the 400 or 351M in Australia. The 302C and 351C were produced in Australia from 1972 to 1982.
At least two things make the Australian Cleveland block different than its North American cousin. As a rule, Aussie Cleveland castings don’t have Ford North America casting numbers (as mentioned earlier), though it is believed some of the North American molds were shipped to Ford’s Geelong, Australia, foundry for those fi rst Aussie castings, which means there are some with North American Ford casting numbers cast in Australia. Another belief is Ford North America shipped discontinued Cleveland casting molds to Australia in 1974 when production ended here.
The terms “D” block and “square” block refer to the boss that rises from the left-hand block deck near the distributor above the fuel pump. D blocks have a D-shaped boss and square blocks have a male or female boss. Early 351C blocks have the D boss primarily, which may have been a provision for a water temperature sending unit on some earlyproduction blocks (but I haven’t seen enough of a production pattern to confirm this theory). I’ve also learned Ford Australia never produced a four-bolt main Cleveland block though they’re as easy to convert as their US counterparts. So, don’t be surprised if you find an Aussie Cleveland street block with four-bolt mains.
Another point to be mindful of is obscure block castings hidden away in race shops, garages, and barns. These rare blocks can be very limited production pieces to factory experimental “XE” and “SK” castings. I’ve seen factory aluminum Cleveland blocks, unusual iron blocks with heavier webbing and pan rails, you name it, most with the XE factory experimental casting identification.
There isn’t a consistent pattern of XE and SK numbers. These blocks followed convoluted paths all over the world from North America and Australia, leaving us with more questions than answers. You may find these block castings at estate auctions, garage sales, eBay, Craigslist, classified ads, old dusty race shops, and other places. You find them completely machined and partially machined. Sometimes, you find raw castings. Expect to also see rough-cut Cleveland blocks with 3.990-inch unfinished bores. And, expect to see some that have never been hot with standard-size bores.
According to various sources online, some XE blocks found their way into regular production because they weren’t acceptable for racing (bad core shift and thin cylinder walls), but worked well in passenger vehicles. That makes your Cleveland block search a crapshoot because it is unknown what you will find out there. Another find known as the “pillow” blocks are race blocks that have bulges or “pillows” in the external block walls.
It has been often theorized in Internet forums that the Xs and Ys in the lifter valley of most Cleveland blocks means a higher nickel content, but Ford has never confirmed this. It’s like that old story of Mexican blocks being of higher nickel content than their US counterparts, which has never been proven beyond hearsay and bench racing. Mexican blocks and US blocks weigh within a pound of one another, which means there’s no difference in nickel content. It is believe the Xs and Ys were cast in to prevent cracking, a running production change in Cleveland blocks.
Although I try to touch on just about everything you might find, there are going to be unusual, limited-production castings that surface breaking all the rules and posing new questions. There has been factory Cleveland development documentation dating back to 1965 that tells us this engine was in development for a long time before it debuted late in 1969. Factory race shops knew about the Cleveland long before it entered production making it Ford’s own mystery engine, not unlike the big-block Chevy.
Early Cleveland blocks seem to have been plagued with cracking issues in the lifter valley. And when they cracked, coolant found its way into the oil. It appears the best Cleveland block to use is the D2AE-CA casting. Though the Ford Master Parts Catalog indicates the D2AE-CA block is a four-bolt main casting, not all of them were drilled for four-bolt mains. Always pull the pan to confirm before committing to a D2AE-CA block casting.
Written by George Reid and Republished with Permission of CarTech Inc