The 1957 Ford Thunderbird was offered with four engine options, three of which were based on the 312 5.1-liter Y-block V-81. The E-Code package was the most rare aspect of the car, and added a pair of Holley four barrels, aluminum intake manifold, Hi-Performance camshaft, and a choice of transmissions. Only the double-quad 312 V-8 models received the E designation in the VIN code. There were 1,499 Thunderbirds equipped with a 312 cubic inch engine that featured two four-barrel carbs (E code).