how much would you say to take off of the 243's theres a local machine shop that does big name high end motors. i was thinking of getting some 243's ported and decked and 07+ intake port matched to it. how much would you say to take off by decking? im gonna run a stock headgasket. also should i have them machined for bigger valves? im looking for a magic combo to make it scream to the moon