My 72 Pantera has been sitting 5 yrs. Upon starting it up it would backfire thru the carb if given a quick WOT. If reved up slowly it won't backfire. I have rebuilt the carb,had the heads redone, changed distributors, reset the timming every which way and still the backfire. Vaccum gauge shows 14-15 steady, reved up to 2,500 rpms it will go to 18. Compression is 95 lbs. Increases 10 lbs if oil is put into the plug hold. Runs very rich,no oil smoke though. Is my cam wiped?