In my experience all the race 440's run on the ragged edge of safe. That being said i would stay away from the pipe and work on your clutching. I have towed too many 440's home. In fact that is what kept me from buying a 2003 prox440 at HayDays.
They are great sleds, quick and nimble. Clutching will help you get the power to the ground. after that i would look at gearing depending on what you want the sled to do. If you want a better sound look for a new silencer/can, this will be much safer than the pipe. Just my opinion.
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