I had two sets of stock Eddy RPM heads flowed, I sent Jeff one set and he picked them up 32 CFM by using his CNC program on them, the reults where on the same flow bench by the same tech. at a machine shop I trust and use(Pettis Performance) They didn't have a interest or a dog in the fight in the results It is way better to have the flow(power available) and not need it than to not have enough flow(power) when you need or want it