Yeah and the mags also tell you that this or that gives you 20% more HP also.So lets see if I add this intake 20% gain those header 20% gainetc.Must be a waste of time to build an engine.Just add the stuff they tell you.We arent talking someones 3rd cousin twice removed.Most people that answered use them and they work.If you have to worry about a few ponies build a bigger motor.Ive seen more guys with $1000 rad clutch fans or electrics with overheating problems than not.My 65 is pretty much a full race car thats street driven.The OE rad that has never beem touched with flex fan runs at 180 all day even racing.Rocky