If you do a search you should find all the info you need in old threads, this question gets asked at least once a month. A quick and dirty answer is the only 660 shock that will work is the rear one from a 2001, none of the yfz shocks are safe to use, nor are the front raptor shocks, and the rap 350's shocks will fit but aren't much of an improvement. Banshee shocks are the right size and will bolt up, they aren't necessarily a better shock but if you're looking for a smoother ride in the trails they will help.