Since this forum deals with 'big bolts' and is more active than other vintage truck sites, I'll ask this here: what was the interchangeability of 1950s 20" stud type wheels? My limited knowledge is that GM does not interchange with Ford, Dodge, etc, but that some do. I have some 5 stud wheels, circa 50s....are they Ford, Dodge or would they fit multiple makes? Also, were there differences in center opening as well as stud (bolt) diameter? I can't seem to find any good references on the different 1.5 to 2.5 ton disc wheels of that decade.

1955 GMC 630, 1959 GMC W660, 1958 Chevy Spartan 80