Rear spring hangers

[Seanext]

I have what I was told was a 1972 short bed 4x4 frame. It came with correct front and rear axle numbers for that year. The rear had 54 inch springs. When I started looking at the mounting it was clear that it was originally 56 inch. The spring hanger were still riveted on so I know they had not been moved as there was no extra holes in the frame. I held a 52 inch spring in place on the front hanger and the spring mount for the front is about a 1/2 inch to wide for the spring. I looked close the hanger is still riveted no extra holes and the spring hanger is not bent. I have measured all the cab mount points and bed mounting points and it is correct for a 72. Did they use a wider spring in the rear for any reason? Was the GMC rear spring wider? I am scratching my head trying to figure out what is correct.

[argonaut]

That is weird. All 72s would have used a 52" x 2.5" wide rear leaf. When holding a spring remember that the bushing adds another 1/2" or width. Also remember that the spring lengthens once the weight of the truck is put on it.

[Seanext]

I have two other 4x4 frames and the spring hangers are about 1/2 inch wider where is spring mounts. Everything else measures the same on all the frames ( cab mounts, core support mounting, front springs, all cross members, everything works. Going crazy here trying to make sense of all of this.

[junksaver]

67 & 68 4x4 trucks had 56" rear springs that are 3" wide. Do a search on those 2 years. The rear springs are odd balls compared to the other years.

[Seanext]

Thanks for the info that makes more sense. I guess the next question is does anyone have a set of rear 56" springs the would like to part with?