 From their inception in the 1950s until the early 1970s, Pontiac engines were known for their performance.The largest engine was a massive 455 cubic inch V8 that was available in most of their mid-size, full-size and sports car models.At the height of the horsepower era, Pontiac engines reached a powerful 390 rated horsepower (SAE gross), though other engines achieved considerably higher outputs in actuality.