Mater
I just installed a frame mount hitch in my '48. I got it for free, but I have also seen the same in scrap yards. It has bolt-on side flanges that bolted to the frame of the donor truck. I had to cut these down, and re-weld them in a 90 deg fashion to lay on top of the frame, and the receiver peeks out just below the rear bed cross member, above the stock bumper. I have several drop heads, but it may require a straight head...still have that to work out. It will handle a heavier load than the truck will pull!!!