The S&S is a great carb. I ran one for a few years. If set up properly you shouldn't have to adjust at high altitudes. I took one over the Italian/Swiss alps and didn't have any troubles. BUT, I went back to my CV. The S&S is just to much carb unless you got big inches and horsepower. That carb suck ALOT of air. If you stay mello, you can get comparable gas mileage, but with a CV, you can open it up and still get great mileage. With an S&S I've done as good as 50+ mpg and as bad as mid 20's mpg with the same settings, but very different speeds . It's a very tempermental carb. Like Manny said you will be better off with a modified CV or from what I've heard, Mikuni, but I have no real world experience with them.