My car had 373's in it when I bought it. I like them, but like they said if I were building a n/a car with occasional racing in mind i'd go 410.s with the 373's I max out at the strip in third about 300 to 500 feet from the finish line an there really isn't time to hit 4th. some day a blower will solve this. I picked up a bassani o/r x pipe off craigs list for $60, I don't think I want to do the long tubes due to the trouble of installing them, then having to remove them for clutch work.