Pontiac 428 V8 Engine

The Pontiac 428 was introduced at the same time as the Pontiac 400 V8 in 1967 and used primarily in the Grand Prix, but also for the legendary GTO and Firebird models.

Although the 428 was modeled after the Pontiac 421, it had a cast iron crankshaft rather than the steel used in the 421. The 428 was one of the “long journal” V8 engines that Pontiac produced.

Because the 428 was used only in large cars like the GTO and Firebird and featured prominently in NASCAR stock cars, it was quickly replaced by the Pontiac 455 in 1970. The higher output 428 engines featured 1.91 inch valves and a 1.66 inch exhaust.

Engine Specifications

  • 1967-1969 with 4-Barrel Carb
  • Max Brake Horsepower = 260@ 4600rpm (factory modifications increased hp to 270 in some models)
  • Max Torque = 472 @ 3200 rpm
  • Stroke = 4.0
  • Bore = 4.12
  • Compression = 10.5
  • Firing Order = 18436572
  • 1967-1969 High Output with 4-Barrel Carb
  • Max Brake Horsepower = 360@ 4600rpm
  • Max Torque = 472 @ 3200 rpm
  • Stroke = 4.0
  • Bore = 4.12
  • Compression = 10.0
  • Firing Order = 18436572
  • Get Ready to Explore Engines Like Never Before

    We hope you enjoy EngineFacts.com! Dive into our growing library of engine specs and fun facts. Whether you’re researching for your next car, satisfying your curiosity, or dreaming up a custom project, Engine Facts has you covered.