I know a guy that took his 65-66 and made it into a 4x4. He tok a early 80's rolling chasis from a Chevy suburban, and all he had to do was refab the body mounts.

Let me know i'll send you link to his wabpage on his truck.
You don't see to many 4x4 60-66 chevy trucks, go for it!! I think these trucks look cool as a 4x4.
Chevyboy62