Rear bumper brackets

[mblackburnjr]

I recently scavaged a set of rear bumper brackets off of a lwb fleet gmc.
I then attempted to mount them with a new bumper(non step) on my 71 swb fleet chevy. They may have been a little bent,but i still dont have the outer ones bent right to match the holes. It sits in a little on pass. side.
Tonight while browsing lmc, I noticed they listed two different sets for fleetsides.1 for swb,1 for lwb.....
So are they different? I would've thought all fleets the same.