There is a new product out called Dial-A-Jet. It installs on your carb and supposedly you can change the jetting just by turning a dial. IT says it automatically makes small changes for you to compensate for altitude, air density and other variances. It "inducts" fuel similar to EFI but not electronic. Im not sue about all the details but check out their webpage, www.thunderproducts.com it only costs $69.95 and if it really works Id say its well worth it. If anybody knows anything more lets hear it. If you have one, even better, inform us about what you know.