Many parts will be the same. Of course many will be just for the 3800. I suggest you buy a Shop Manual for that truck from Jim Carter's or any of several vendors. Go to the links page on this site. I have a 50 3600 3/4-ton and bought most of my stuff for it from Chevy Duty (now Classic Truck Parts) but others on here have had good success with other parts sellers. All sheet metal for your truck cab will be same as 1/2-ton or 3/4-ton. All 4-speeds (SM 420) from that era are the same except the tail end has that ball/socket/flange for the torque-tube on 1/2 and 3/4. Your brakes will be specific. Does yours have 18" wheels? Tires may be hard to find in that size. Good Luck!
