Tech & Auto
The Real Difference Between Pontiac 400 & Chevrolet 400 Engines
By MIKE SHUTT
Although General Motors often shared designs and parts across its various brands, Chevrolet and Pontiac developed their own V8s in the mid-1950s.
Both brands released a V8 with a 400 cubic inch displacement. Although they were essentially made by the same company and called a 400, these engines weren’t the same.
Pontiac made its block V8 in 1967. It was similar to Chevy’s except that all its V8s were the same external size, and the different displacements were done through bore and stroke.
Chevrolet created its 400 engines in 1970. While the engine was similar to earlier designs, it used Siamesed cylinders, which prevented coolant from circulating between them.
While the designs for the two engines aren’t remarkably different, the Chevrolet 400 could generate up to 265 horsepower, while the Pontiac 400 produces 360.
Therefore, the Pontiac 400 was made as a high-performance muscle car engine, while the Chevy 400 was primarily used on pickup trucks.