1968-1972
All GM A-bodies were completely restyled in 1968. The 400 cu in limit remained. In 1970 the 400 cu in limit was removed, mainly due to Chrysler's domination in the drag racing and muscle car market with larger engines and highest power rated engines available in nearly all models. This led each of the four GM divisions to offer their largest engines: Chevrolet's 454 cu in (7.44 L) in the Chevelle SS-454, Pontiac's 455 cu in in the GTO, Oldsmobile's 455 cu in in the 442, and Buick's 455 cu in in the GS.
The two-door had a 112 in (280 cm) wheelbase; four-door, station wagon, and the El Camino had a 116 in (290 cm) wheelbase; and the stretched-wheelbase wagon had a 121 in (310 cm) wheelbase.
Also using a variation of the A-body chassis and suspension were the 1969-1972 Pontiac Grand Prix and 1970-1972 Chevrolet Monte Carlo — both of which were marketed as intermediate-sized personal luxury cars and coded as G-body cars. The Grand Prix had a 118 in (300 cm) wheelbase and the Monte Carlo had a 116 in (290 cm) wheelbase. When the A- and G-body cars were restyled for 1973, the G-body design was renamed the A-special body.
Read more about this topic: GM A Platform (RWD)