Fox-

Had a similar dilemma with the Nova front clip in my '51. Ultimately, it was easier to use matching Nova mounts for my chevy small block and use the existing holes. I would suggest using Chevy mounts that fit the 350 (perhaps from your '83) and try to place them by mocking up the drivetrain. You'll need to check the distance between the firewall (HEI clearance can be tricky) and radiator (fan clearance may depend on long or short water pumps).

Others may have better measurements handy. My frame just went into winter storage and I can't give you good numbers. :rolleyes: