Swap

[dpearson]

I have a 75 Jimmy with 454, th350/205, dana60 and a 14 bolt rear. I was wondering if I could swap the Gen II drive train into a Gen I?

 

[70~K5]

You would have to move the rear spring mounts and use gen 1 springs on the front. Or you could move the front spring mounts and use the longer springs The rear mount are wider on a gen 2.

 

[SilverJim]

I couldn't have fit my big block into my truck without the 3" body lift...even after that, the valve covers were awfully close to the firewall.
For the drivetrain, as long as modifying the spring perches is not a problem, the swap is easy.

You can use small block motor mounts for the big block, but that can sometimes create oil pan clearance problems with the front crossmember.