We’ve shown you two early 1960s NHRA Super Stock engines from Chevy (409) and Chrysler (413) and today for 4/21, we’ll show one more: Pontiac’s 421 Super Duty. Put into the luxurious Catalina, the potent 421 was perhaps the most raucous of the race-bred Super Stocker mills. Even in the big chassis, Pontiac’s beefy V8 got the job done against the Chevy Bel Airs and Impalas, the Dodge Darts, and the Plymouth Fury.
Like its other Super Stock compatriots, the Super Duty was an evolution of the Pontiac’s ever-expanding V8 displacement. Increasing returns from stock car pushed the company to build a bigger and crazier V8, although to homologate the engine (and a chassis for it, the Catalina Super Duty), Pontiac had to build 50 examples. What they turned out was one of the more extreme engines of the day. While advertised at 405 horsepower, the big V8 likely made considerably more than that. Hemmings (linked below) wrote that the engine probably made closer to 460 horsepower, which is a ludicrous figure for an engine on the dealer options sheet.
Ironically, the Super Duty looked mostly like a regular Catalina two-door aside from a different set of wheels. Otherwise, you’d mistake it for a grocery getter, at least until the throaty 421 cranked over. Depending on who you ask, however, the sedate-looking coupe could cover a quarter-mile in either the high 11s or the mid 12s. Hemmings wrote a great piece on the 421 Super Duty back in 2005 that you should read right here. Pontiac kept the 421 around for several years, though not in Super Duty trim. Our sister publication, Muscle Car Review, found a mid-’60s Pontiac 421 on its way to salvage back in 2014 (above). You can read all about its restoration and rebuild in five parts: Part 1, Part 2, Part 3, Part 4, and Part 5.