The 1962–1963 221-ci and 1962–1964 260-ci engines employ five-bolt bellhousing blocks with a bore of either 3.500 (221) or 3.800 (260) inches. Casting numbers are C2OE, C3OE, or C4OE. The location of these casting numbers depends on the block. In 1962, block casting numbers were cast into the rear lifter valley rail on top. In 1963–1964, they can be found just above the starter. Casting date codes in 1962–1964 are in the block above the starter. These blocks are easy to spot because their 3.500- and 3.800-inch bores are smaller than the standard 4.000-inch found on the 289 and 302.
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Block-deck cooling passages on the 221 and 260 are triangular shaped as well, which makes them different from the 4.000-inch-bore 289 and 302. Early 1962 221 and 260 blocks had two 11⁄2-inch freeze plugs on each side, which became three freeze plugs in 1963 with the arrival of the 289. These early blocks are also identified via engine-mount bolt-hole spacing; the earliest 221/260 blocks are 5.940 inches apart along with two freeze plugs instead of the traditional three you see most often. Revised engine-mount bolt-hole spacing to 7.000 inches changed in the 1963 model year to reduce noise, vibration, and harshness.
The 289-ci engine entered production in the 1963 model year with a five-bolt bellhousing bolt pattern just like the 221 and 260, along with the 7.000-inch mounting bolt holes and three freeze plugs on each side of the block. Five-bolt-bellhousing 289 blocks have casting numbers of C3OE, C3AE, C4OE, C4AE, and C4DE.
Beginning with the 1965 model year, Ford revised the 289 block to a six-bolt bellhousing bolt pattern to improve noise, vibration, and harshness. Block casting numbers are C5AE and C6AE. The 289 High Performance V-8 had the same block as the 289-2V and 289-4V with the exception of wider main bearing caps. Standard 289-2V and 289-4V main bearing caps are 15/16-inch wide at the block main saddle; they taper as they rise to the top at the casting and cap numbers. The wider 289 High Performance main bearing cap is 15/16-inch wide at the block and does not taper. This difference applies to both five- and six-bolt-bellhousing 289 High Performance blocks.
The 302 block appeared for the first time in the middle of the 1967 model year in 289 applications with a C8AE or C8OE casting number with a “302” in the valley area. What made the 302 block different than the 289 was .015-inch-longer cylinder skirts to accommodate the 302’s longer 3.000-inch stroke. It is not uncommon to find a 1967–1968 289 engine with a 302 block.
The 302 block evolved after 1968 with casting revisions. Although most of these blocks are interchangeable with 289 types dating back to 1965, it is important to note that the clutch equalizer shaft pivot boss on the driver’s side was eliminated from the 302 block beginning in 1975. This means that you need a bolt-on clutch equalizer shaft pivot bracket for a 1975–up 302 block if you run a manual transmission and the classic Z-bar clutch linkage.
If you restore a classic Mustang or other type of vintage Ford, your search for a corresponding numbers-matching block is challenging because there aren’t as many salvageable cores as there used to be. For the purist, remember this: The block should have a correct casting number. A 1965 Mustang, as one example, should have a C4 or C5 casting number depending upon vehicle build date. Casting and engine build date codes should fall within 30 to 60 days of the vehicle build date.
One example might be “5A26” (January 26, 1965), which means year, month, and day of casting or manufacture. If the date code is cast into the block, it indicates the exact date the block was cast. If it is stamped into the block, it indicates the engine’s exact date of engine assembly.
If you find a matching-number block with cylinder bores that have been bored to 4.030 inches or larger, the block can be sleeved by a qualified machine shop and returned to service. The cost to sleeve a block is approximately $100 per cylinder depending upon the shop and area. The good part about sleeving a used block is the seasoned iron from steady cycling of heating and cooling over time. Sleeving is discouraged if you’re going racing because, no matter what anyone tells you, there isn’t enough stability with iron bores. New-old-stock Ford service blocks from the 1960s are expensive and hard to come by but can still be found.
Check any block you’re considering for cracks and severe deck warping before machine work is performed. This process can be accomplished by any qualified machine shop before expensive machine work begins. As a rule, small-block Fords rarely suffer from cracking unless there has been a severe overheat or extraordinary circumstances such as an accident or the block having been dropped. Weak spots are generally around the decks near cylinder head bolt holes, cylinder bores, and main saddles.
Mexican 289/302 blocks are believed to have a higher nickel content, but this is not true. Mexican blocks and their north-of-the-border counterparts weigh virtually the same, which debunks the high nickel content theory because nickel adds weight to an iron casting. A Mexican 289/302 block is better because of its wider 15/16-inch non-tapered main bearing caps (as you see on 289 High Performance blocks). Mexican blocks are a good source for wider main caps. If you use them on another block, have a machine shop measure and line bore/hone them to the proper size.
Ford’s limited-production 1969– 1970 Boss 302 engine block is highly sought after for its four-bolt main caps, heavier main webs, thicker decks, and screw-in block plugs. Because fewer cores are available today, it isn’t racers going after these blocks but restorers looking for authentic date-coded Boss blocks.
Five basic Boss 302 block castings were produced: C8FE, D0ZE-A, D0ZE-B, D0ZE-C, and D1ZE-B. C8FE is the 1968 302 Tunnel Port block, which was also used in production 1969 Boss 302 Mustangs and Cougars. Most common are the D0ZE and D1AE Boss 302 block castings. D1ZE-B is a Ford replacement service block. Because Boss 302 engines failed mostly due to piston failure, there are plenty of service blocks available.
As with the earlier 221, 260, 289, and 302 blocks, overbore for the Boss 302 block is limited to 4.040 inches, and it is suggested no greater than 4.030 inches, especially if you intend to take it to 7,000 to 8,000 rpm. You can sleeve a Boss 302 block for about $100 per cylinder and go back to a standard bore.
Compared to the 221/260/ 289/302, the 351-ci Windsor block is a taller deck with additional webbing in front on top, which makes identification easy because it has a wider block. The 351W has a 1-inch-taller deck to accommodate the increased 3.500-inch stroke. The 1969–1971 351W blocks appear to be stronger than those after it based on having a higher nickel content.
Early 351W blocks are numbered C9OE and D1AE. One other option is 351W blocks cast in Mexico for high-performance applications. They are difficult to come by. They pop up from time to time in U.S.-built Fords and Mercurys. Like the 302 blocks mentioned earlier, these blocks weren’t limited to Mexican-built vehicles.
Finding a Cleveland block with a standard bore is challenging because so many of them have been rebuilt or recycled into scrap iron. Most have been bored to at least 4.030 inches. Boring them beyond 4.040 inches is discouraged. As with other small-block Fords, 351 Clevelands can be sleeved and brought back to standard for about $100 per bore by a qualified machine shop.
Two basic 351C blocks, two-bolt main and four-bolt main, were produced with casting numbers visible above the starter. This information enables you to identify these blocks without removing the oil pan. Although there are two basic blocks, there are several casting and part numbers.
Ford Australia produced a NASCAR Cleveland block for the North American market; however, not much is known about this block. These blocks had thicker cylinder walls and decks along with four-bolt mains. The bad news is that they were rejected and returned to Australia due to casting core shift problems and sold on the Australian performance market.
Not all 351C engines produced in Australia employed blocks cast in Australia. According to reliable sources, Ford’s Cleveland foundry and the Michigan Casting Center produced 351C blocks for Ford Australia with North American casting numbers. Michigan Casting Center blocks received an “MCC” logo/code. Blocks produced both in and for Australia were used for both 302- and 351-ci engines. Ford Australia-produced Cleveland blocks are identifiable by their cast-in thermostat coolant-flow restrictors instead of a brass insert such as the North American 351C. These blocks have Ford Australia casting numbers.
The 400 and 351M engines use the same raised-deck Cleveland block. This block has a 1.091-inch-taller deck height (10.297 inches versus the 351C’s 9.206 inches) to accommodate the 400’s 4.000-inch stroke. This makes a 351M/400 block easy to identify. However, most 351M/400 blocks have a Ford big-block bell-housing bolt pattern, which means you need to use a big-block C6 or Top Loader for a raised-deck Cleveland engine project. This is the same bolt pattern used for the 385-series 429/460-ci big-blocks but not for the FE-series 390/427/428.
One Ford insider closely involved with Cleveland engine development said that the 335- series engine family was originally going to have a minimum of 335 ci, which explains the “335” designation. The 335 became 351 ci with the same bore and stroke as the 351W along with the same bore spacing.
Cleveland blocks were designed for four-bolt main bearing caps, which didn’t happen until well into production. Ford engineers wanted more iron underneath for added strength without a skirted block and cross-bolted main caps. They also wanted an engine with minimal potential for leaks, hence the dry intake manifold and steel-plate front timing cover.
Although Ford produced 302 and 351C engines in Australia, none of the Australian blocks was fitted with four-bolt main caps. Australian Cleveland blocks did not have traditional North American Ford casting numbers, though it is believed North American casting molds were shipped to Australia when 351C production ended in 1974. If you find a Cleveland block devoid of a Ford North American casting number and a “GF” foundry designation, you’ve found an Australian block.
The orifice plate below the thermostat on the 351C engine block controls coolant flow to the thermostat and should never be removed. If you do, you will have thermostat malfunction and resulting overheating issues. Ford called this the “Controlled Bypass System.” The new coolant-control system provided improved cooling without frequent thermostat cycling. It also provided for improved warmup. When Ford introduced the 400, it eliminated the orifice plate, instead molding the Controlled Bypass System into the block.
Although the 400 and 351M engines receive a lot of criticism and not much respect, there’s more to these overlooked engines than meets the eye. The 400 and castrated 351M are criticized because they were never developed to their potential by Ford. Had things gone differently in the 1970s with more of an eye on performance, the 400 could have easily been factory grown from 430 to 450 ci, a mid-size block with a big-block personality, without the weight penalty. The 400 could have easily been what the 351C became. And with good cylinder heads and deep-breathing induction on top, the 400 block can be grown aggressively in terms of displacement and power.
All 351C block castings, despite having different casting numbers, are basically the same 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. Without the casting numbers and date codes, these blocks defy detection except for minor casting changes. Any Cleveland two-bolt main block can be converted to a four-bolt main if you have the stock four-bolt iron or aftermarket steel billet caps.
Cleveland discussions become confusing regarding the 351C versus the 400 and the 351M. Although the 400 is generally called the 400M, it has never been called “400M” by Ford Motor Company. The raised-deck 400 Cleveland, first introduced for model year 1972, was always the “400.”
When Ford destroked the 400 to 351 ci and called it the 351M in 1975, people started calling the largest Cleveland “400M.” The 400 and the 351M both use the same block casting that was in production from 1971 to 1982, though they have different part numbers. The “M” designation was conceived to differentiate the 351C from the raised-deck 351M, which replaced the 351C in 1975.
Cleveland engine builders are stumped by the nuances that aren’t explained in 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 (that can be drilled and tapped)?
The Australia Connection
Did you know that Australian Cleveland blocks are clearly different than their North American counterparts? Although the Cleveland V-8 is as popular in Australia as the small-block Chevy or 5.0L Ford is here in the United States, Ford never produced the 400 or 351M in Australia. The 302 and 351C were produced in Australia from 1972 to 1982. The Australian Cleveland block is different from its North American cousin. Australian Cleveland castings don’t have Ford North America casting numbers, though it is believed that some of the North American molds were shipped to Ford’s Geelong, Australia (GF), foundry to produce those first Australian castings. This means that there are some with North American Ford casting numbers cast in Australia. Another belief is that Ford North America shipped discontinued Cleveland casting molds to Australia in 1974 when production ended.
In Cleveland circles the terms “D” block and “Square” block refer to the boss that rises from the driver-side block deck near the distributor above the fuel pump. “D” blocks have a “D”-shaped boss and “Square” blocks have a male or female square boss. Many people believe that early 351C blocks primarily have the “D” boss, which was actually a provision for a water temperature sending unit on some early-production blocks. Unfortunately, with only a minimal production pattern, this theory can-not be confirmed.
Ford Australia did not produce a four-bolt main Cleveland block though they’re as easy to convert as their U.S. counterparts. So, don’t be surprised if you find an Aussie Cleve-land street block with four-bolt mains.
XE and SK Blocks
Obscure block castings may be hidden away in race shops, garages, and barns everywhere. These rare blocks can be very limited-production pieces or factory experimental “XE” and “SK” castings. Aluminum Cleve-land blocks, unusual iron blocks with heavier webbing and pan rails, you name it, were produced, most with the “XE” factory experimental cast-ing identification.
Most of us wish for 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 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, unmachined 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.
Although this book tries to cover just about anything you might find, there will be unusual, limited-production castings that surface, breaking all the rules and posing new questions. For example, “Pillow” blocks, are race blocks that have bulges or “pillows” in the external block walls.
Cleveland development documentation has been found dating back to 1965, which indicates that 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 motor.
It has been often theorized in the online 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 is believed the Xs and Ys were cast in to prevent cracking, a running production change in Cleveland blocks.
Ford Racing Blocks
Ford Racing Performance Parts (FRPP) offers high-performance blocks for small-block Fords. Everything from a modest 5.0L street block to an all-out race block is available. This section concentrates on street hardware. The most significant block introduced by FRPP was the Boss 302 block, M-6010-BOSS302. It was basically a replacement for the 302 M-6010-A50 Sportsman block that was in production for many years.
The M-6010-BOSS302 block is cast with the latest high-tech techniques at Ford’s Cleveland foundry, which has a long legacy of great engine castings including the 221/260/ 289/302 small-block and 351 Cleve-land. Refining this technique came from years of practice developing durable NASCAR blocks that have a fierce reputation for reliability. What makes today different than the 1960s is computer-aided-design (CAD) used in casting modeling.
Once Ford adds virtual machining to the casting model, it’s time to calculate how much molten metal needs to be poured into the sand casting. Although this process saves Ford money, it also saves weight. Cylinders are siamesed to make the block stronger. Although the new Ford Racing Boss 302 block has had some teething problems, it has become one of the best aftermarket blocks Ford has produced in a long time.
The classic Ford Racing Sportsman block is an excellent value if you can find one. The disappointing part was the halt in production of these A50 Sportsman blocks, which were such an excellent value for the money at around $1,000 each new. And if you’re building a warmed-up street engine, the discontinued 1985–1999 5.0L production roller block has also been a great disappointment because Ford gave you the option of starting with a new stock block instead of searching all over for a standard-bore used block.
The M-6010-A50 Sportsman block is a great value because there are plenty available, both new and used. Tipping the scales at 135 pounds, the Sportsman block offers nodular iron architecture with wide two-bolt main caps. These blocks can be stroked to 347 ci. FRPP suggests no larger than 4.030 inches. The A50 Sportsman block is a great direct replacement for the bread-and-butter 1985–1999 5.0L roller block.
Although FRPP offers more race blocks than street blocks, it makes decision making easy when you’re building a street machine or a weekend racer. The M-6010-BOSS302 is a great street/strip block, but a bit cost prohibitive if you’re on a tight budget. The A50 Sportsman block is more practical in terms of cost, yet it is no longer available from FRPP.
Mission and budget determine which block you choose. Without any doubt, the A50 Sportsman is a more practical block for street and strip. You can throw 450 hp at this block without spending a fortune.
Buying a Used Block
Selecting and buying a used engine block doesn’t have to be baffling. First, what is the engine’s mission? How will it be used? If your objective is racing and you need a race block, you have many options. Ford Motorsport SVO and FRPP have produced many race blocks in the past 20 years. This means there are a lot of new and used castings out there. As you shop around, carefully inspect and always measure any block you’re considering. Look for signs of overheating, cracks, discoloration, and deck warpage.
Written by George Reid and Posted with Permission of CarTechBooks