Originally Posted by kel1306

Another thought, are the box floors for narrow frame trucks the same as those for the wider frame trucks?

Originally Posted by ChaseTruck754

This won't answer your main question but hopefully it will help a little.

Having just put an '87 (pretty positive it was an 87) bed on my '74 F-100 supercab 2wd I can tell you the bolt holes in the beds aren't exactly the same like I had read...

From what I had heard/read the inside of the beds were the same from 73-96 - aside from the holes being in a different spot for the 4wd trucks that had the narrow frame rails.
While I had a bed on my '74 I was going to be cutting the stock bedsides off and replacing them with flared fiberglass bedsides. A guy had asked me if I could sell my bed and after thinking about it for a bit and reading the 80's and 90's beds would "bolt on" I told him if he gave me some cash and a replacement bed in decent shape I would. Since 80's and 90's beds are easier to find and cheaper this worked for him.

Well I got the 80's bed on and there are some differences. For starters the 87(?) bed I got uses 6 bolts to hold it on instead of the 8 my '74 had. Granted you can see where the 2 other bolts would/should go and there is a hole in the bottom of the bed - but it doesn't come up through the top layer of the bed skin.
I have the 2 rearmost bolts in the bed through the frame and the other 4 from the 80's bed are slightly off from the holes in the frame on the '74. I didn't spend a ton of time looking at it as I was just setting the bed on there for now, but it seems as if the holes in the frame on the '74 are about 1/2" or so outside of the holes in the bed. They are close, but not close enough to get the bolts to go through.

So the shortened version is - the beds are close and will swap but I'd expect to drill some holes.

Here's pics of the bed/truck I was referring to.

Originally Posted by scottfreeman

That is an interesting idea......I wonder if one could do the same with some steel skins.....take an '80s-'90s inner bed and put the '70s skins on it......I remember the inners looking similar between all 3 decades.....Could be a good way to get a cherry floor for a nice resto.....since most of the '70s beds prolly need new sides anyhow....