ha good luck, best bet is to tie a string around the pulleys and buy 2 belt sizes bigger, and 2 smaller and return the ones that dont fit. No matter what number anyone gives you its probably not going to be right.
I think My belt was somewhere around 95" or 97" This was with a A/C & Smog Delete Pulley with factory 302 brackets. You want to pay attention to the little arrow on the tensioner. You Don't want it too tight or too loose.