Originally Posted by BC_Dan

First thing most people do is get an aftermarket pipe and can. They usually increase HP and decrease weight, so you get a lot of bang for your bucks. Then clutching would be next, usually adding a pipe also changes the powerband, and you have to clutch it to get the RPMs to where the power is. Is your sled carbed or EFI? You may have more limitations on what you can do with the EFI model.

Have you checked out ArcticChat.com? That is a Cat specific forum, there are a lot of guys that have a TON of info on tuning all sorts of cats. I'm betting they can give you some pretty specific info regarding what works best for your application.