I was wondering how much cylinder head flow specs help when a cam selection is made? I have two sets of oem heads with many many many hours of work invested and was wondering if I should have them flowed before asking for a cam suggestion. Or would port volumes be good enough? I'm sure a general recomendation could be made but if the flow specs reveal some things that would help with a cam selection making 20 or more HP then it would be worth laying down the extra $100 per pair to have them flowed.