I know I've seen those front mount bolt holes in a 350, but I don't know which ones have them and which don't.
The bellhousing behind the GMC 302 will NOT fit a Chevy V-8.
The 'minimal adjustment' V-8 approach is probably a Chevy V-8 using a truck or pickup V-8 bellhousing from a '55 to '66 or '67. Actually, starting in '63 a six bellhousing should be the same.
I think the GMC motor even has the same flywheel bolt pattern, so its possible the flywheel and clutch will work... I'm not real sure of that...
I'd front mount the motor if you are still using the bellhousing mounts instead of messing with a new crossmember.
Use a cable type throttle. You'll change a few wires and move the radiator and should quickly and easily be back in business.
