The Stovebolt Forums Forums The Shop Area Making a Stovebolt Bed rear cross sill 51 3/4 ton

I've searched through the archives and still have a question about this. When we got the truck the bed was just strapped to the frame, not bolted. Yes we towed it home. Now I'm ready to attach it to the frame. The mounts on the rear cross sill need to be about 5" more towards the frame to meet and sit on the frame. The frame also needs to be about 3 1/2" longer to sit under the rear cross sill. The mounts will catch the frame but I don't think and inch or 2 is enough support. this is a long bed which measures 88 3/4' long as measured along the top rails.
Questions
1) Was there a bed that year that would have been a few inches shorter?
2) What is the measurement between the mounts on other 51 3/4 ton longbed trucks?
3) Did some models come with a bracket or steel plate bolted as an extension for both length and width so as to line up with this rear cross sill?

I have my rebuilt bed mounted except for the wood I will look tonight and send the measurements for the mounts. I will shoot some pictures of my mounts also in the mean time I will send you some links that explain how the mounts work and it may give you a better idea.

Sounds like you have a 1/2 ton rear sill instead of a 3/4 ton rear sill. The frame end mounting bolts on a 1/2 ton are about 44-1/4 apart and the 3/4 ton frame is about 33-3/4 apart.

GMC made a 1/2 ton long bed, but Chevrolet only made 3/4 ton long bed trucks in 51. Your bed may be from a GMC

The frame extends under the rear sill mounting bracket, but not under the rear sill.

Mar-Ktech

Thanks for the information. The mounting brackets on the rear cross sill are the 44 1/4" measurement. So I have a 1/2 ton bed or at least a 1/2 ton rear cross sill on 3/4 ton frame. It is a 51 Chevy, so the long bed is correct. At this point I am thinking of having a frame extension bracket made up for both the length and width needed to use the rear cross sill mounts that are there. Maybe a little gussett under the bracket.
Thanks Martin

The only difference between 1/2 ton and 3/4 ton rear sills is the location of the brackets. You can remove and re-weld the brackets in the right place or replace them with new ones. Correct replacement brackets are available separately.

Mar-Ktech