Rear bumper brackets, 4X4 versus 2 wheel drive

[AirSpeed]

I just bought a brand spankin new Chrome rear bumper for $75 (bragging). It's going on my 72 GMC 4X4. I need to order rear bumper brackets. Some catalogs show brackets specific to 4X4 trucks, others show the same brackets for all. I measured the frame on my 69 C-10 and it seems the same as my 72 GMC 4X4. Is there a difference that I'm not seeing?

[71blksuper4x4]

Yes, there are differences in the rear inner brackets. Some are designed for coil spring trucks and leaf spring trucks. Others are designed for swb and lwb. Trevor

[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.