will a 1977 short bed match a 1986 cab?

[Laine]

hey everyone i'm building a 1986 GMC short box 2wd and i'm trying to find a fleet side short box for my project and not having much for luck.......i found a couple 1977 boxes that need some tlc but just wondering what the differences where?
any help would be great

 

[78C10BigTen]

I do believe that the fillers are different and the older boxes didnt have a door like the later ones, the neck bolted to the body and the cap went right on the neck. Keep your ears open for others advise on this though.

 

[hatzie]

The body lines will match up but you have to deal with the filler necks.

The fill hoses on the early trucks were different diameters. The diameters changed after 1980... not sure if it was 81 or 82 or 83.
73-77 had fillers right through the side of the bed with no doors so you can't just swap the fill necks to the later size like the 78 and later beds.

 

[Laine]

thanks guys! i just looked at my original message and realized i forgot to mention the frame was a 1980.....when i bought it, there was a 1980 cab with a 81-87 front end on it.
it didnt have a VIN on it so i bought a 1986 gmc sierra and plan to put it all together here soon!