Rear bumper brackets, 4X4 versus 2 wheel drive

[71 super]

The original 4x4 inners have a brace welded on the inside, they will look like an after thought or home engineering, but they are factory reinforcements. The swb 4x4 and maybe short gmc with leaf springs used these, the long wheel base 4x4 uses the same brackets as regular coil spring truck due to the location of the rear spring perches. If you want the bumper to fit correctly you need the right brackets for the swb. Wes at classic heartbeat carries them as does GMC Pauls as well as others. You will spend as much for the right brackets new or used as you did for your bumper. Hope this helps.