ok 1st of all , all chevy muscle cars have  codes on the cowl  tag to tell what size motor n trannys that was in the car .  n wat trim  is supose to be on the car . n there r vin codes on the tranny  n motor  n rear end .  you just have to do ur home work  n know ur chevys  n ask alot of Q's . but dont belive everything  the seller tells  you on the phone. there  r  tons of books out there  2 decode the engine codes n tranny codes , n rear end codes , n never go look at a car at night or in the dark with  a flash light .always go n look at it during the day n bring a small magnit  2 see where the bondo spots r . good luck hunting . signed :  robert - diehardchevys.