"...engines from full sized Pontiac's and Grand Prix's..."
So, is a '69 -'77 GP considered a "big car", or an A-body, or does it have it's very own designation ?
"...The G-body designation was originally used for the 1969–1972 Pontiac Grand Prix and 1970–1972 Chevrolet Monte Carlo personal luxury cars, which rode on longer wheelbases than A-body coupes.
For 1973, the Grand Prix and Monte Carlo were folded into the A-body line, with all formal-roof A-body coupes designated as A-Special (and, after 1982, G-Special). These special coupes included the Monte Carlo, Grand Prix, Oldsmobile Cutlass Supreme, and Buick Regal.
For the 1982 model year, GM introduced a new front-wheel drive A platform for its mid-size car lines. The rear-wheel drive platform that had been in use since 1978 was re-designated as the G platform, and select models remained in production..."
Most of the junkyard 455's I bought came out of Grandvilles.