I am putting my '59 on a '85 K1500 frame,they are the same width.Another option for you may be to junk the I beam front axle and bolt on a complete front suspension crossmember from any '73 up GM 1/2 ton or van.This will give you good suspension and disc brakes,you will need to adapt the steering.I was going to do this before I decided to go the 4x4 route.
ed
