I ended up finding a two ring Saginaw with a 3.11 first gear for $100 locally. It seems like the newer three speeds in 71-72(?) C10s had the longer tail shaft that would match the length of the four speed Saginaw, so I should be able to find a used driveshaft from one of those trucks pretty easily. I'll update the thread with pics once I start the swap.

Last edited by theastronaut2276; 06/08/22 04:53 PM.

1966 Chevy C10 Driver/Pro Touring Build
http://67-72chevytrucks.com/vboard/showthread.php?t=474456