The automaker's answer was a 7.0-liter, 426-cubic-inch displacement engine. It used the same block as Ford's earlier 427 FE V8 but incorporated numerous performance upgrades to improve power output.

Monster motors were the order of the day in the late 1960s, and GM's 427 was a part of that class. The drawback to a big-block's burly output was, and still is, the increased weight of the engine.