I used an under bed carrier from a square body truck 74 to 87 I believe.Had to trim the one end slightly ,maybe a half an inch .The original ones are hard to find in my area .Mine was done years ago so I just got one from the junk yard .I also can’t remember if the top u shape braces that go across to both sides of the frame were part of it .Anyway here is a few pictures ,the picture of the pieces on the floor are from the net but is what I got from the junk yard.The wind up ones may be a better choice like said above you don’t have to crawl as much on the underside of the truck.
