I used a ZR2 Blazer spare tire rack on my old truck:
The upper bracket needed extensive modification, and the latch bar bracket for the tailgate had to be notched to clear the tailgate release handle. Of course major reinforcements were needed as well. It took some nerve to drill six holes in the rear fender and five in the tailgate. It is not "perfect" , but it does work and almost looks stock.
Over the years I did acquire a ding in the fender at the front of the lower mount. The carrier was not latched and swung open on a hard turn to the highway. Lots of force there and it crinkled the fender a little. My fault for not checking the latch. A secondary latch safety might have been a good idea.
I mostly liked it. I did have issues trying to haul stuff in the back with the tailgate open. Usually I'd strap the rack to the back an pull it against the tailgate. Kind of a hassle if you're trying to haul a motorcycle. A rare occurrence at that time.
Would I do it again? Probably not. It was unique and did serve my purpose very well, but it was lots of work and kind of in the way with the tailgate open. JMO.