318 advice

Off hand, I can not think of the Pirple cam specs. Headers allways help sound and mufflers of course. BJR can tell you how much to mill the heads. Your ratio is about 8.5-1 with that piston down .080 and assumed head chamber of 65cc and a 4.06 X .028 gasket, (or close to it) which would be the stock head gasket. (AKA MoPar thin head gasket.)