The solution always used to be a "test pipe"
No, 302's were never stock in *the* over 8,500 gvw 250's without a cat, but was the cat integral to the Y-pipe, like 300's?

"Cat eliminators" were always popular in the Mustang community.
The engine bay and routing were a bit different (especially with 4x4) but I'd really be surprised if you couldn't find one that fit.
Also, while an exhaust shop is never going to risk a federal fine or having their state license pulled, a mom-n-pop type place would probably make one 'for off road/track use only.'
I know that I could go over to Four Way Garage and have
anything bent. Even if they won't install it on something driven off their lot.
In fact their Tee shirts say "Get Bent with 4-Way" 😄😄😄
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.