I need some pointers on who to clutch my 600 ho fusion to make better off the line and mid range and top end

I'm not very clutch savvy, so I can't really answer your question, but you may have better luck posting this in the Fusion & IQ forum. This forum section is primarily for ATV's.

I'm certain you'd have a much better chance of getting a response there. I have read about what works best for the 600 HO in other forums, but I never tried them, so I don't want to speculate and give out false information.