In 1970, Pontiac introduced a mid-year curiosity called T-37. Touted as Pontiac’s cheapest two-door hardtop, the T-37 was a submodel of the Tempest, which didn’t have a hardtop in its roster at the beginning of production. Everything from a Chevrolet straight-six to a 330-horsepower 400 was available, which was notable because 1970 was the first time an engine bigger than 350ci was available in something other than the GTO. There even was a sporty GT package to create the GT-37, which played the dual role of cosmetic supercar (due to its standard 350 two-barrel) and Road Runner-fighter (due to the available 400).

For 1971, the T-37 completely replaced the Tempest. Pontiac also allowed any engine to be installed, meaning the 455 (previously only available for the GTO) was now available. Though all Pontiac engines featured lowered compression to the tune of 8.5:1 or less, engineers had something up their sleeve with the 455 HO. What they did was take the round-port heads from the 1969-70 400 Ram Air IV and put them on the 455 — something they should have done in 1970 while compression was still at normal levels. The 1971 455 HO was rated at 335 gross horsepower, which didn’t sound like much, though in net measurements it was 310, which came off a bit more substantial.

Though long overshadowed by high-compression engines, the 1971 455 HO (and the nearly identical 1972 version) has come into its own as being one of the ultimate street engines of the era, full of low-end torque, able to use pump gas, and capable of outgunning high-compression competitors. Only 936 GTOs (including 374 Judges) were built with the 455 HO. Another 122 A-bodies were built with the same engine. Of those, only 15 T-37 two-door hardtops had the 455 HO.

Join Muscle Car Campy as he tells us more about Kevin Guido’s Q-ship Poncho, one of those 15.