Known in the beginning as the 90-degree Fairlane V-8, for its first vehicle application in 1962, the small-block Ford began its service life modestly at 221-ci with a 3.500-inch bore and 2.870 inch stroke with an Autolite 2100 2-barrel carburetor. What made the 221 innovative was its lightweight gray iron, thin-wall construction, which made V-8 power possible in compact- and intermediate-sized cars. Because the small-block Ford was an “oversquare” design, meaning bore size was larger than stroke, there was room for larger valves, reduced piston speed, and shorter connecting rods allowing higher RPM. More iron in the main webs permitted 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 engine technology at the time.
This Tech Tip is From the Full Book, HIGH-PERFORMANCE FORD ENGINE PARTS INTERCHANGE. For a comprehensive guide on this entire subject you can visit this link:
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The 145-hp 221-ci V-8 was a smallblock with very low displacement. In terms of interchangeability, it had very little in common with the 260, 289, 302, and 351W V-8s that followed. The 221’s cylinder heads employ very small ports and closed 43.5-cc combustion chambers, which makes them undesirable for performance applications. And the compression ratio with the 260/289/302 was too high, making 221 heads unacceptable in any case. The 221 was available only with an Autolite 2100 2-barrel carburetor with automatic choke, making it very short-lived, lasting through the 1963 model year.
Introduced at the same time as the 221, Ford’s 260-ci small-block made 164 hp via 3.800-inch bores and the same 2.870- inch stroke as the 221. The 260’s cylinder heads had larger 53-cc chambers with the same 1.590/1.390-inch valves also found in the 221. Valvestem size also stood at 0.310- inch, just like the 221. Also like the 221, the 260 was available only with Autolite 2100 2-barrel carburetion. The 260 was also a short-lived engine, with production ending in 1964. Both the 221 and 260 were mildmannered mills (at 8.7:1 compression) for use with regular leaded fuels of the era. Carroll Shelby began his two-seat Cobra production with the 260 topped with a Cobra high-rise manifold and Holley carburetion.
Ford conceived the 289 in 1963 and increased bore size to 4.000 inches while staying with the small-block’s original 2.870-inch stroke. The 289 can easily be viewed as one of Ford’s most successful engines ever, thanks to an incredible performance history at LeMans, Indianapolis, Sebring, Daytona, and dozens of other racing venues around the world. Forget the logic saying you can bore a 260’s 3.800- inch bores to 4 inches to make it a 289, because you cannot. There’s simply not enough cylinder wall thickness with a 260 block to get there safely. You have to begin with a 289 or 302 block. The 289 block is a thicker casting, designed for those larger 4.000-inch bores. The same can be said for the 302 block, with its extended (by .015 inch) cylinder skirts to come later on in 1968. In fact, the 302 block first showed up in the 1967 model year stuffed full of 289 internals—the “1M” crank with 2.870-inch stroke, C3AE rods, and cast pistons.
There are a lot of misconceptions about the 289. I am here to set the record straight. All 289 cylinder heads, including High Performance versions, have the same port, valve, and chamber dimensions. Intake valves are 1.670 inches. Exhaust valves are 1.440 inches. What makes the 289 High Performance head “high performance” are valvespring pockets for stability, along with screw-in rocker arm studs engineered to withstand high RPM when compared to press-in studs. Otherwise, 289 High Performance heads aren’t any different than standard 289 castings. If you desire the features of 289 High Performance heads without the Hi-Po price, upgrade the 2V/4V head to screw-in rocker arm studs with pushrod guide plates and valvespring cups and you have the same result for less money.
In the 289’s first year, 1963, there were two basic engines: a 2-barrel version with Autolite 2100 carburetion like the 221 and 260, and the 289 High Performance with Autolite 4100 4-barrel automatic choke carburetion and mechanical tappets, 9.0:1 compression, cast-iron exhaust headers with automatic choke heat stove, and 289 High Performance-specific heads. In 1964, Ford added a third 289 to the mix with 4-barrel carburetion and the same compression ratio as the 2-barrel available in Mustang only (“D” engine code).
California emission standards first manifested in two ways in 1964: closed crankcase ventilation, and the use of a PCV (positive crankcase ventilation) valve, the latter also used on most 49-state cars. I’ve seen no rhyme or reason behind how these engines were equipped and distributed outside of the California emissions closed crankcase ventilation system. Some 289 engines were fitted with PCV valves while others were fitted with a draft tube. Some 1964 289 engines were fitted with timingcover oil filler tubes while most were located in the left-hand valve cover. Combustion chamber sizes in 1963–1964 ranged from 52.6 to 55.6 cc for all 289 engines. Chamber size depended upon the casting. All 1963–1964 289 engines had five-bolt bellhousing blocks just like the 221 and 260.
Another important issue here is engine identification. Although I get into casting identification elsewhere in this book, valve-cover style and air-cleaner color identified Ford engines prior to 1966. All Ford engines were primarily black with valve covers and air cleaner in specific colors for identity purposes. Beginning in 1966, all engines were painted Ford Corporate Blue and remained that way until the early 1980s, when color changed to gray, then, ultimately bare iron and aluminum.
Important upgrades in the 289 occurred for the 1965 model year beginning in August 1964. The most obvious was a block casting change from a five-bolt bellhousing pattern to six-bolt to reduce noise, vibration, and harshness (NVH). Aside from this important change, the 289 remained essentially the same, with the base 289-2V engine keeping 52.6- to 55.6-cc combustion chambers and dished pistons to keep compression at 9.0:1. Valve sizes remained the same. For 1965, the 289-4V engine went from sharing dished pistons and the same compression ratio to 10.0:1 and flattop pistons.
All pistons, flattop and dished alike, had valve reliefs. The 289 High Performance V-8 remained virtually unchanged aside from the six-bolt bellhousing block and a higher compression ratio.
The 289 didn’t change for 1966, aside from engine color, which became Ford Corporate Blue for all engines. California emission standards became tougher for 1966, calling for not only closed crankcase ventilation, but also the Thermactor air injection pump system to help further burn unburned hydrocarbon emissions.
Effective May 2, 1966, 289-2V and -4V engines received important cylinder head and valvetrain changes you need to be aware of, including the use of railstyle rocker arms, longer valvestems, revised cylinder head castings, and pentroof valve covers. These pent-roof-style valve covers were in production through the 1967 model year. One subtle change during the 1966 model year was the short-term use of a finned timing cover, used through early 1967. Although the 289 High Performance V-8 never employed rail-style rocker arms, it did use pent-roof valve covers with a chrome finish and a high-performance openelement air cleaner for 1967.
Because Ford’s 289-ci V-8 witnessed such great success across the board as both a dependable street engine and a world-beating performer on the racing circuit, you wouldn’t think Ford would disturb this success, but it did. Pressure from increasing displacements at Chevrolet, Pontiac, and Chrysler pushed Ford toward adding more stroke to the tried and proven 289 to get 302 ci. The additional stroke was challenging to even measure at .013 inch, bringing the small-block Ford’s stroke to 3.000 inches. As was mentioned, Ford had to revise the block, extending cylinder skirts .015 inch for improved piston stability at bottom dead center. Some 1967–1968 289 engines got 302 blocks. This happened toward the end of the 1967 model year before the 302 entered production.
Although the 302 has a longer 3.000- inch stroke, it has a shorter connecting rod (5.090 inches center-to-center), which is not interchangeable with the 221/260/289 rod (5.155 inches center-to-center). The 302’s shorter rod, when combined with the longer 3.000-inch-stroke 2M crankshaft, gives this engine its increased displacement. Aside from the minute differences just mentioned, the 302 is virtually identical to the 289, including valve size and combustion chamber design. One exception is the 1968-only 302-4V head with smaller 53-cc chambers and higher compression. What makes 1968 engines visually different than 1967 versions are the words “Power By Ford” stamped into their pent-roof valve covers. These words appeared on all Ford valve covers that year and until 1975, when they were replaced by the Ford corporate oval.
The 302 has evolved considerably since its introduction in 1968. Beginning in 1978, Ford began calling the 302 the “5.0-Liter” V-8, as the United States became pressured to employ the metric system. In 1978, Ford also began fitting the 302 and other engines with a stamped-aluminum air cleaner to reduce vehicle weight.
When Ford brought the Mustang GT back in 1982, it fitted the timeless pony with a High Output version of the 5.0L V-8. Although quite lame by today’s standards, the 5.0L high-output had a high-performance 351W marine camshaft (and 351W firing order) coupled with a Motorcraft 2150 2-barrel carburetor and dual-snorkel aluminum air cleaner. The engine’s bottom end also changed to accommodate the increase in performance. Instead of the 289/302’s 28-ounce offset dynamic balance, the 5.0L High Output had a 50-ounce offset balance, which is very important to remember when you’re building these engines. Get it mixed up and you have unwanted, severe engine-punishing vibration.
In 1983, Ford began fitting the 5.0L High Output V-8 with a Holley 4180 4-barrel carburetor, which was a Holleydesigned and Ford-engineered performance/ emissions/tamper-proof carburetor. This carburetor, aside from minor engineering changes, remained essentially the same through 1985 along with the Motorcraft Duraspark II ignition system. In 1985, the 5.0L High Output V-8 received an all-new roller-tappet block designed to accommodate roller cam technology to improve power and fuel efficiency. In 1986, the small-block Ford received the most dramatic change in its history—port fuel injection. Known as Sequential Electronic Fuel Injection (SEFI), this new system of fuel delivery and spark control (EEC-IV) was the single biggest quantum leap in technology for the Fairlane V-8 because it wasn’t just port fuel injection. It was a complete electronic engine management system.
Although the 5.0L SEFI engine was intimidating for a lot of people in the beginning, enthusiasts ultimately embraced this powerplant and went racing with a new attitude known as PRO 5.0—building powerful Mustang rocket ships. It was so successful that it spawned a new organization known as the NMRA (National Mustang Racers Association), which has become a huge Mustang subculture. An exciting new chapter for the industry was born, and it shows no signs of letting up. Despite a drastic blow to the economy since this book was first published more than a decade ago, enthusiasts are still racing the 5.0L small-block Ford in record numbers. The 1986 5.0L High Output SEFI engine also came with a new “Fast Burn” cylinder head borrowed from the F-Series truck parts shelf. The 5.0L High Output V-8 has grown to become one of the most respected highperformance engines of our time.
Ford enthusiasts have long called the 221-, 260-, 289-, and 302-ci engines “Windsor” V-8s. However, the only true “Windsor” engine is the 351-ci raiseddeck small-block Ford introduced in 1969 as a response to the cubic inch race going on in Detroit. Although the 221/260/ 289/302 engines were all manufactured at Ford’s Cleveland engine plant, there are crossovers that required clarification. Not all 289/302 blocks were cast at the Cleveland foundry. Quite a few were also cast at Windsor with a “WF” cast in the lifter valley. Most Cleveland castings received a circled “C,” but not all of them did. Some blocks were devoid of any kind of foundry identification, which makes it tricky to identify them.
To achieve the 351’s displacement, Ford had to raise the 302’s deck 1 inch to accommodate the 3.500-inch stroke. Bore size remained the same at 4.000 inches. To improve power, smoothness, and reliability, Ford gave the 351W a different firing order than the 221, 260, 289, and 302 engines. Beginning in 1982, the 302 (5.0L) received the 351W’s firing order for the same reason. Ford insiders from the period tell us the 5.0L engine was switched to the 351W’s firing order to more equally distribute stresses across the crankshaft.
The 351W employs a heavier wall thickness around cylinder bores and main webs. Interchangeability with other small-block Fords is considerable, enabling all kinds of swaps. The 351W, for example, has the same bellhousing bolt pattern as the 289/302 six-bolt blocks, making it possible to swap this engine into 289/302 powered vehicles. The 351W also accepts 289/302 engine mounts. Cylinder-head bolt and bore patterns make head swaps straightforward. Where it becomes challenging is the 351W’s cooling passages between intake manifold and cylinder heads. Early 351W cylinder heads have dog-legged cooling passages, making it necessary to modify intake-manifold gasket passages. The 351W’s cylinder heads are a great budget horsepower swap for 289 and 302 engines because they employ the same block deck patterns. These desirable heads have larger ports, valves, and chambers, which make them a great budget swap. Larger chambers do mean reduced compression ratio. Keep this in mind anytime you’re considering a head swap.
The 351W nodular-iron crankshaft has larger main and rod journals than the 289/302, along with a longer stroke. With this crank came longer connecting rods (5.956 inches) than you find inside the 289/302. New for 1969 was the only 351W-4V engine ever produced with 10.7:1 compression ratio. The 351W-2V engine had a more modest compression ratio of 9.5:1. The 351W-4V was equipped with the Autolite 4300 4-barrel carburetor while the 351W-2V was fitted with the old reliable—an Autolite 2100 2-barrel. Ford never produced a high-performance 351W V-8 prior to the Lightning F-150 with the 5.8L V-8. All were fitted with flat-tappet hydraulic camshafts until the advent of roller-cam technology in the 1980s.
Ford’s legendary Boss 302 engine remains one of the most significant high performance power plants in the company’s history. It was world beating, and it is surely symbolic of the end of the classic muscle car era. The Boss 302 engine happened when Ford decided to get out of racing. Think of the Boss 302 engine as a wonderful act of desperation, because the 1968 302 Tunnel-Port was such a miserable flop for Ford. In theory, the Tunnel-Port cylinder head was a great idea, making a whopping 450 hp at 8,000 rpm. Problem was, racers needed to push it to nearly 9,000 rpm to make checkered-flag power, scattering these engines all over racetracks from coast to coast. Because this problem was epidemic, Ford engineers had to think fast and arrive at a solution everyone could live with in order to salvage a hard-won reputation for winning.
We may never know which came first—the Cleveland engine or Cleveland cylinder head. But, we do know Ford’s engineers took the 351C-4V poly-anglevalve wedge head and used it on the 302- ci engine to achieve peak horsepower in the 6,500- to 7,500-rpm range instead of a rod snapping 9,000. All it took was cooling passage modifications to these Cleveland castings (because the 351C has a dry-intake manifold and the Boss 302 has a wet one), which was easy in production. Boss 302 engines had 1.73:1-ratio rocker arms mounted on screw-in studs with adjustable fulcrums. All had flat-tappet high-performance mechanical camshafts.
The Boss 302 block began life as the 302 Tunnel-Port block with a “C8FE” casting number, four-bolt main caps, heavier webbing, forged-steel 3.00-inchstroke crankshaft, heavy-duty connecting rods (actually “C3OE” 289 High Performance rod forgings with 3/8-inch bolts and meatier shoulders), and TRW forged aluminum “pop-up” pistons designed for Cleveland wedge chambers. Compression was 11.0:1. Don’t be surprised to find a C8FE block in an early 1969 Boss 302 Mustang, because quite a few made it into production cars. The rest were surplus castings left over from the Tunnel Port days, which made it into the Ford Muscle Parts program and dealer pipelines.
Other Boss 302 features included a dual-advance, dual-point distributor that was a Boss 302 exclusive. On top, the Boss 302 had a 780-cfm Holley 4160 4-barrel carburetor. From 1969 through early 1970, Boss 302 engines were fitted with chrome-plated, stamped-steel valve covers. Early in the 1970 model year, Ford went to cast-aluminum valve covers. Ram-Air was not available on the Boss 302 until the 1970 model year. Ignition systems included a dual-point, dualadvance/ retard Autolite distributor.
There has been a lot of debate through the years why Ford did two engine families displacing 351 ci: the 351W and 335-series 351C. The 351 Cleveland is a small-block V-8 with the attitude of a big-block thanks to very innovative engineering features. It has always been long on torque and high on horsepower thanks mostly to its cylinder heads. The 351C has never been very productive with low-end torque because its 4-barrel cylinder heads were designed primarily for high-RPM power. That begs the question: Why did Ford put this engine in car lines never intended for high-RPM use, such as the Galaxie, LTD, Fairlane, and Torino? We’re convinced this is why the 351C was short-lived, with a brief four-year production life (1970–1974 in North America). It was never practical to produce two engine families employing the same displacement.
Because the 351C has at least two GM nuances to its architecture (block configuration and poly-angle-valve cylinder heads), it raises questions about how this happened. Although this has been a point of speculation for years, I have to admit it looks suspicious from any angle. The 351C block looks like a Ford/Oldsmobile hybrid with 289/302/351W bore spacing and size coupled with an Oldsmobile V-8’s frontend architecture. The Olds-similar features include abundant cast-iron and a steelplate timing cover, 12/6-o’clock-bolt fuel pump (the only Ford V-8 ever to have the 12/6 fuel pump), and a cast-iron water pump. On top, the Cleveland’s poly-anglevalve cylinder heads with those large ports and wedge chambers closely resemble Chevrolet’s 396/402/427/454-ci big-block castings of the era.
The 351C is identical to the 351W in terms of bore spacing and size. However, the 351C block is a completely different casting designed to take on larger cylinder heads with poly-angle valves, huge wedge- and bowl-shaped chambers, and smaller 14-mm spark plugs. The 351C is a higher-revving V-8 thanks to large ports and improved breathing. Also different from the 351W is the thermostat’s block location instead of on the intake manifold as you find with the 289/302/351W.
The 2- and 4-barrel versions of the 351C were produced right from the start with 9.5:1 and 11.0:1 compression ratios, respectively. Compression was determined by combustion chamber size. The 4-barrel head has a wedge chamber, where the 2-barrel head has a larger open chamber to reduce compression. The downside to the 2-barrel head’s open chamber is pinging and detonation issues that make it undesirable. On the upside are smaller intake and exhaust ports for improved low-end torque. The best Cleveland head out there comes from Australia, with the 4V wedge chamber and 2-barrel intake and exhaust ports, making it the optimum cylinder head for this engine.
Like the 351C, we may never know what led to the 400M in 1972 and ultimately the 351M in 1975. But, we do know the 351/400M engines weren’t one of Ford’s better ideas meaning there are better choices out there for engine builders. The 351/400M was a raiseddeck (one-inch taller) Cleveland with larger 3.000-inch main journals (which made it taller and wider than the 351C) designed to accommodate the 400’s 4.000-inch stroke. The 400M debuted in 1972 to replace the FE-Series 390-ci bigblock in full-sized Fords and Mercurys. For manufacturing cost efficiencies more than anything, Ford destroked the 400M to 3.500 inches to conceive the 351M for 1975. Common belief is the M-Series Clevelands were Ford’s effort to make the most of this engine family in North America before it decided to call it quits in 1982.
The 400M is a “square” engine, meaning it has the same bore and stroke dimensions. The tall-deck 400/351M has 351C-2V heads with huge open 76.9-cc chambers, which make these heads a poor choice for any Cleveland engine project because they lose compression and are prone to pinging and detonation due to poor quench. Another important issue to remember with the M-Series engines is their big-block bellhousing bolt pattern, which makes them incompatible with small-block transmissions.
Like the rest of Detroit in the late 1970s, Ford looked for ways to squeeze more mileage from a gallon of gasoline. The 255-ci small-block was a short-lived answer to a challenge that’s still plaguing us 30 years later—fuel economy. Produced from 1980 to 1982 only, the 255 never cultivated a performance image because that’s not what it was designed to do. The baby Ford small-block had the same 3.000-inch stroke as the 302 with a smaller 3.68-inch bore. It had 255-specific cylinder heads with smaller combustion chambers and valves with round ports, and absolutely no performance potential whatsoever. The 255 was a very shortlived chapter in small-block Ford history and with good reason.
Written by George Reid and Republished with Permission of CarTech Inc