I assume you mean the flares, not the fenders? If so, they won't work - the ZR2 flares are cut short in the front because of the ZR2 bumper, so they won't work on the front of a non-ZR2.
The AIR design flares are very similar, and do fit the non-ZR2 trucks. That's what I went with.
Ok yeah i'm really confused. I just went through the "how to make ZR2 flares work on a Trail Boss" quest two months ago so of course that's what my brain read. Turns out that wasn't the question at all, and there's really no way to make the question make sense.