Torquing pressure plate to flywheel

My husband removed a T5 and hydraulic clutch from a 1985 Camaro 2.8L and is rebuilding the clutch. The clutch disk bolts are 8mm and another forum said they should be torqued to 50 #'s. They break at around 30#'s so he purchased new ones, and likewise. We do not have a manual for this application, and do not wish to buy one just for this one time. He checked a couple other manf. Manuals and for lightweight v6 it was only 20#'s or so. Can you please give us the recommended torquing for this application?