[dennislbrooks]

For rear 12 bolt 3.73's are easy to find from a half ton and you should be able to find a Dana 44 or gm 10 bolt with a 3.73 and lockouts. Brakes can be moved. 4.10 may be more common from a 3/4.

I have 2 extra -- 12 bolts with 3.73's - one from a 67 c10 with leaf spring perches and the other from a 69 K10.

Leaf spring perches and shock mounts can be moved on rears if needed.

Shock mounts can be moved on the fronts.

But your need may require 4.10's.