Join Date: Mar 2002
Location: Austin, TX, USA
Virgil, I think the only difference between subframes as far as block size is the motor mounts. They unbolt, so keep what you've got and find any 1st generation subframe to replace it with. In addition to first gens, Novas, Omegas, and Ventures (I think) from 72 - 74 used almost the exact same frame. The only difference was the holes drilled for engine mounts and other cosmetic stuff. My 68 has a 73 Nova subframe in it. You'll find this topic in this forum or the body forum archives giving great detail.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI