The Tempest line received another facelift for the 1970 model year. Hidden headlights were deleted in favor of four exposed round headlamps outboard of narrower grille openings. The nose retained the protruding vertical prow theme, although it was less prominent. While the standard Tempest and Le Mans had chrome grilles, the GTO retained the Endura urethane cover around the headlamps and grille.
A new option was Pontiac's 455 HO engine (different from the round-port offerings of the 1971–72 cars), available now that GM had rescinded its earlier ban on intermediates with engines larger than 400. The 455, a long-stroke engine also available in the full-size Pontiac line as well as the Grand Prix, was dubiously rated by Pontiac as only moderately stronger than the base 350 HP 400 CID and less powerful than the 366 hp (273 kW) Ram Air III. The Pontiac brochure indicated the same 455 installed in the Grand Prix model was rated at 370 horsepower (280 kW). The camshafts used in the Ram Air III and the GTO 455 HO were the same.
Source: Wikipedia (original)