Besides port and polish, what else can be done? Have read u can put chevy valves in it, but that dont seem right. What is the best cam for the 300? 94 efi 300 by the way. May rebuild engine this year, gonna go with 19 lb injectors. Gonna change throtle body off a 351, want a good exhaudt that if free flowing but fairly quiet any suggestions? Read some where that i could bore it .50 over and put 390 pistons in it, would that make the walls real thin?