Rear receiver hitch…..
 

Will a 1972 Blazer receiver hitch work on a 1972 Sububarn 4x4 or are they different?

I thought there was something unique on the 1972 Blazer rear frame?

Re: Rear receiver hitch…..
 

Until 1972, the Blazer frames were flat on the ends, and the bumper was mounted using two brackets on each side that attached to the frame.
In 1972 they extended and semi-rounded the rear portion of the frame and mounted the bumper directly to the frame ends, and added an additional outboard mounting brace.
I don't know about the '72 Suburban frame, but I would guess that it may be made the same way?