Ford Small-Block Engine Parts Interchange. George Reid

Fairlane V-8. Instead, 302 and 351W engine production continued and the 335-series engine family faded away in North America.

      Because of the big move to go metric in the 1970s, Ford went from using cubic inches to measure displacement to liters and centimeters. In 1978 the 302 became known as the 5.0L V-8 and remained such until production ended in 2001. The short-lived 255-ci, a small-bore 302 with 3.000-inch stroke, was employed in 1980–1981 as a means to fuel economy.

      The 351 Cleveland that arrived in 1970 quickly developed a performance image for itself thanks to large-port heads, wedge chambers, and rugged block architecture. The downside to the 351C on the street was its large ports, which delivered lackluster low- to mid-range torque, yet came on strong at high RPM. The 335-series block was an overweight design with an inadequate oiling system, which begs the question why use it at all if you have the option of a 351W-based engine? There is also a strong loyalty to the 335-series block, which has inspired the aftermarket to get on board with a couple of different blocks with great strength and better oiling systems.

      Ford Australia did more with the Cleveland than did Ford’s North American Operations. It improved the Cleveland block’s shortcomings and created just the right combination of port size and combustion chamber design, building a far better 351-ci middle-block than Ford North America ever did. We will probably never know the entire story of why Ford did a parallel family of 351-ci engines.

      It has been said that the 351 Cleveland came as a result of former General Motors boss Semon E. “Bunkie” Knudsen’s brief presidency at Ford Motor Company during the late 1960s. Because the 351C has poly-angle valves like a big-block Chevy and block architecture resembling Oldsmobile’s Rocket V-8s of the era, it is logical to assume Knudsen brought these nuances with him from General Motors via the engineering staff that followed him. However, it remains unknown as to how or why this engine became a reality.

      The 351C had abundant torque at high RPM; it was a small-block Ford with the attitude of a big-block. Production of the 351C ended in 1974 in North America and in the 1980s in Australia. This leads us to the 351M and 400 middle-block V-8s. The 400 was a raised-deck version of the 351C introduced in 1972 to replace the FE-series 390 in passenger cars and ultimately in trucks. To improve manufacturing efficiency, Ford destroked the 400 to create the 351M in 1975, which enabled Ford to use a single block casting for both displacements. When the 351C was discontinued, it was replaced by the 351M. Externally, the 351M and 400 are identical in appearance. This makes the 351M a poor choice for an engine build. You might as well take advantage of the 400’s displacement because there’s virtually no difference in weight and size.

      Although a lot folks call the 400 the “400M,” it was never so designated by Ford. It was introduced and recognized as the 400 in 1972. The 351M uses the “M” designation to differentiate it from the 351C, which is a different block. The debate continues as to whether Ford called it Midland or Modified.

      The small-block Ford’s production history spans nearly 40 years.

       CHAPTER 1

       GENERAL DATA AND SPECIFICATIONS

      Ford’s popular small-block V-8 began its production life at 221 ci with a 3.500-inch bore and 2.870-inch stroke topped by an Autolite 2100 2-barrel carburetor with automatic choke. What made the small-block Ford innovative was its lightweight gray iron and thin-wall construction, which made efficient V-8 power available in compact and intermediate-size cars. Because the small-block Ford was an “oversquare” design, meaning bore size was larger than stroke, it received larger valves along with reduced reciprocation speed and shorter connecting rods, allowing higher RPM. Plenty of iron content in the main webs allowed for the elimination of block skirts found in earlier Ford V-8 designs, which reduced engine weight. The small-block Ford V-8 was a quantum leap in lightweight cast-iron engine technology at the time.

      The small-block Ford was produced in two foundries and engine plants during its long production life: Cleveland, Ohio, and Windsor, Ontario. The 351W was produced exclusively at Windsor. The 221 and 260 were produced at Cleveland only. The 289 and 302 were produced at Windsor and Cleveland, which can be verified by “CF” and “WF” casting marks on heads and blocks.

      According to Ford small-block historian Bob Mannel, more than 500 prototype and preproduction 221-ci engines were dyno tested and evaluated before Ford began mass production, logging 17,000 hours in Ford’s Dearborn Dynamometer Laboratory and 250,000 miles of in-vehicle testing. The 221 and 260 were introduced in the 1962 Ford Fairlane and Mercury Meteor. During the following years, the 221 and 260 proved to be fiercely reliable engines that were both peppy and economical to operate.

      Although these engines are virtually identical externally, there are differences that make them identifiable. The 221 had a hub/pulley adaptor and counterweight. The 260 had a true harmonic dampener. From 1962 to 1965, small-block Fords were identified by engine color: color-coded valvecovers and air cleaners over a black block and heads. All Ford engines were primarily black with valvecovers and air cleaner in specific colors for identification purposes. Beginning in 1966, all engines were painted Ford Corporate Blue and remained that way until the early 1980s when the color changed to gray, then ultimately bare iron and aluminum. Early on, the 221/260 had a timing cover oil filler tube, which was used in production through 1964. Not all engines were equipped this way. Others had a valvecover oil filler neck.

221

      The 145-horse 221-ci V-8 was introduced in 1962. It was a very low-displacement small-block that has very little interchangeability with the 260, 289, 302, and 351W V-8s. It is fitted with the 2.870-inch cast crankshaft yet with no identification mark like the 289’s “1M” crank, which didn’t happen until 1963.

      Connecting rods were “C2OE” forgings of the same length as the 260 and 289. However, these forgings were dropped for the stronger “C3AE” rod of 1963. The 221’s very modest cylinder heads employ small ports and wedge 43.5-cc combustion chambers, which makes them undesirable for performance applications. These cylinder heads are non-players unless you are performing a restoration and want original castings. Compression ratio with 221 heads with the 260/289/302 was too high, making them unacceptable.

       260-2V V-8 in light blue over black in a 1964½ Mustang.

       1964 289-2V V-8 in red over black in a Fairlane.

       289-4V V-8, regular fuel, gold over black, in a 1964½ Mustang with timing cover oil filler.

       Here’s the Mustang-only 1964½ 289-4V low-compression V-8 with valvecover oil filler cap and PCV valve. When these engines had the timing cover oil filler tube, they were not fitted with a PCV valve. Instead, they had the draft tube extended from the rear of the intake manifold or off the passenger-side valvecover. Three or more variations were produced.

      The 221-ci small-block was short-lived with production ending in 1963.

260

      Introduced at the same time as the 221 (in 1962), Ford’s 260-ci small-block made 164 hp via larger 3.800-inch bores and