A very simple, in-expensive make-over for the '63-66 GM trucks is to switch out the front end assembly, cross member, etc., with one from a '73-81 C10. The entire assembly is held in place by 16 bolts and can be done in an afternoon. All the bolt holes line up except for one that has to be elongated. This swap will give the vehicle modern power steering, power brakes.
A late model, '88 or later V8 with a rebuilt 200R4 AOD trans and a GM 343/372 10 bolt rear end will complete the modernization of a tired old truck.
I prefer the '88 and later engines because they are great engines that last for over 200K with very little problems. All of the emission nonsense other than the PCV system can be eliminated because the truck is smog exempt. The 200R4 trans is a non-computer controlled trans that is the same size as a TH 350.
If you want to really up-grade your truck you can do what I did to my '64, I put the '64 body on a '98 Z71 chassis. The truck drives and handles like a new one. At 70 mph the tack shows 1900 Rpm. Wm.
