I saw a car modification show where the took a 1950's long wheel base f6 truck and removed the rivets holding the rear springs and axle on and slid the entire assembly forward. I understand the chevy have a taper on the frame at the rear but what is stopping one from doing the same thing. What would be the issues that may come up if you do this?
I believe others have made SWB trucks out of LWD trucks as you mentioned. Take some measurements to see what may work. If it fits your needs better, go for it. Of course you would have to source a new driveshaft.
