I am starting a project with a 63 ½ ton short wheel base GMC. I have allot of work to do so my beginning is to start with the frame. It is still pretty much original. My dilemma is that I want to change over to front and rear disc brakes, converting it over to 5 lug is not really that important but I think it would be simpler that way. I know that I will still probably have to find another rear end with disc brakes or convert the ones I have that’s not a concern right now. My main concern is that once I take it off the frame I want to place it back onto an updated frame. Which year model tucks should I be looking for to accomplish this swap with the least amount of difficulty? Are all the ½ ton frames about the same or what?