I tried to find a part # for those thick rear bumpers also with no luck.
The heavy 1 ton front bumpers are well documented.... not so much for the rears.
I ran across a rear bumper at a swap meet years ago & I noticed right off that it was thicker & much heavier than a standard 1/2 or 3/4 ton bumper.
It is currently on my truck.
I dug out a 1/2 ton bumper to compare the two & as you can see... it is darn near twice as thick as the 1/2 ton bumper.
This is the only one I have ever seen but....they do exist.
