97 Suburban big block to 64 suburban

[suburban509]

I have a 97 Suburban 2wd with the 7.4 vortec big block and auto trans. The burb is literally falling apart body and electrical wise. I also have a 64 Suburban shell all painted and waiting for a new motor and trans. My latest thinking is why not just put the big block and trans in that. The 64 originally had the small block v8. I've searched a lot on this forum but not finding what I'm looking for. Will the big block motor mounts come close to the original mount towers on the 64? Will that trans fit the tunnel without modification? I'm not worried about the electrical interface with this swap. I will keep the computers and fuel injection of the 97, just the phyisical size and trouble of putting the motor and trans in. Any advice?