Think the set I bought took about 4-5 weeks for delivery. The fronts matched up just fine with my fenders, couldn't test the rears as I still had a broken set on the car. This was for my Y88. I didn't opt for the additional mounting brackets, they're fiberglass afterall, they won't bend so don't waste the money on them unless you're going for a points restore at which point....why are you not looking for GM parts???
I've got some GM originals I'll be using on the 80 firebird.