Current setup is 6lbs boost. Much more fuel. I have them jets drilled quite large. I tried a 17 19 and 21 prop. Boat still seems to like the 17 best. When wot it pulls to about 6200rpm at 46mph and it is screaming. Only did that twice racing my buddy's 195v v6 boat and I can pull him out of the hole up past top speed. So I would say I have completed what I set out to do. The serp belt does seem to wear fast. I'm guessing it will only last about 40hours. Fair amount of belt dust around the charger.... A tensioner pulley might solve this issue.