Highlights

• This engine was an expensive limited option on 1962/63 Catalina and Grand Prix models
• Super Duty motors featured a high nickel cast iron block with 4 bolt mains, forged steel rods and crankshaft, Mickey Thompson forged aluminum pistons, and a solid lifter McKeller #10 Camshaft. It was rated at 405 hp @ 5,600 rpm (but was actually closer to 460 hp)
• The exhaust manifolds were either cast iron (road) or aluminum (strip) and mounted with cutouts. Drag racing versions had two four barrel carbs while the NASCAR version came with one large four barrel
• This 1963 engine is prime example of Pontiac greatness. It contains all the hard to find 421 SD components such as the twin carbs, aluminum intake, big valve NASCAR heads, forged crankshaft, dual point distributor, extremely rare balancer, upside down starter, and split flow exhaust manifolds.