04 thru 08 YFZs are 15.75 eye to eye with the same stroke length as a 16" eye to eye Raptor 700 piggyback shock has. Their a direct bolt on to a 700 (660's need a bit of grinding to fit). The 07 Bill Balance edition and all the 08 YFZs have added high/low speed compression along with rebound and pre-load adjustment as all years of the 700 piggyback type shocks do. If you are needing a set I have a few sets of both models along with Raptor piggybacks too. Or if you just have any questions on the shocks let me know and I'll be happy to try and help..