Went out to the garage last night, did a lot of measuring and thinking. I actually think it might be easier to move the leaf springs from my donor El Camino(this one has leaf springs for some reason) and the rear over and not cut the frame in the center section but cut it at the rear of the truck. My plan is never to carry anything in the back of the truck anyway, so having the added heavy duty rear is not an issue. I want to be able to cruise at 60 and keep the engine that is there and have a standard truck bed in it.
I will probably go back and forth for a while because I am still concerned about the weight of the frame rails and the overall new height of the axle and how to get it even with the current one. I want to run wheels that are close to the front since I will leave the 1 ton fronts on for now till I can afford a swap there too.
All of the 1/2 tons I have found that I could even think of purchasing have been dogs. I think cutting or even moving is easier than a frame swap so that is the reason I am pursuing that direction. I do not mind the bigger tires, I just want the better highway speeds for now.