the big truck fenders are wider but I don't think the inners changed, and while the cabs are all the same regardless of truck size, it's conceivable that the mounts could differ, might take a close look at that between your 2 cabs
did you sort out the rad position problem? I could try to get some measurements from my 58 frame if you have specific points to check ....
here's one I put up for someone, the space from the rad mount bracket rear rivet to the crossmember
Bill
