 The Super Duty 421 of 1962-63 put Pontiac near the top of the charts in factory performance. Factory-rated at 410 hp, this engine was reportedly good for more than 450 breathing through exhaust manifolds! |
As with many of Detroit’s builders, Pontiac introduced their modern V8 in 1955. Displacing 287 cubic inches, it was a decent performer for the time, but its true potential was yet to be realized. Since Pontiac’s marketing strategy was centered around attracting younger buyers, and younger buyers paid attention to performance and racing results, Pontiac developed a series of over-the-counter “super duty” parts to increase power. By 1962, however, the hot-rod parts weren’t simply sold at the parts counter, but assembled at the factory and installed in cars on the assembly line.
To remain competitive in the raging Super Stock wars of the early ‘60s, Pontiac released the 421 Super Duty in 1962. Features include free-flowing cylinder heads with 2.02” and 1.76” valves, forged-steel crank, rods, 4-bolt main caps, 11:1 compression ratio, twin Carter 4-bbls on a high-rise intake, and a camshaft featuring .445” intake lift, .447” exhaust lift, and 308° intake and 320° exhaust duration. This engine was rated by Pontiac at 405 horsepower. For 1963, the compression ratio was bumped to 13:1, and factory-claimed output climbed to 410. The engine was reported to make closer to 450 horsepower, however, while breathing through the factory exhaust manifolds. (It should be noted that very close attention was paid to the design of the manifolds, ensuring that power loss was minimal. Pontiac even cast some of their performance manifolds in aluminum to save weight!)
The infamous GM anti-racing edict of 1963 severely curtailed Pontiac’s racing activities, but was definitely a factor in the release of the 1964 GTO. Pontiac didn’t want to lose their hard-earned performance image, and since they could no longer race openly, they decided to move their performance to the streets.
Pontiac’s street engines were certainly good runners, particularly those with Tri-Power carburetion and functional Ram Air. But the next big development took place in 1969 with the Ram Air IV 400. In 1968 Pontiac offered, on a very limited basis, a Ram Air II engine with new cylinder heads featuring 2.11” and 1.77” valves, revised intake ports and redesigned round exhaust ports. For 1969, these heads were combined with a 10.75:1 compression ratio, a camshaft featuring .516” int/exh lift (with 1.65:1 rocker arms), and 308° intake, 320° exhaust duration. The bottom end featured a heavy-duty nodular iron crankshaft spinning in a 4-bolt main block. The intake was a cast-aluminum high-rise piece with a separate cast-iron heat crossover, and a GM Quadrajet mixed the fuel. Rated at 370 horsepower in the GTO, this was undoubtedly Pontiac’s best performing street engine during the muscle car era.
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While Pontiac is best known for creating the intermediate muscle car with the GTO, their performance history runs much deeper. When Bunkie Knudsen assumed leadership of Pontiac in 1956, the division suffered from poor sales and a rather stodgy image. Knudsen knew the way to sales success was through positive image, and positive image could be created at the race track.