not sure on compression, guy i bought it from said he used the nos on it lots no problem. Also said to run 100 LL, I have a stock 06 800 the head on it compared to mod sled is a lot more to split line. not sure how many .000 were taken off. Bushings on front skis aprox 3/4",i have been told you can put them inside or outside. Increase or decrease distance between skis. can someone tell me why?