This year I did a rebuild. I took my 2008 M1000 and ....
... put a fresh new 2010 motor with new motor mounts (replaced and added new ones cause I'm running so much power I tend to break the mounts), new rear Arctic cat tunnel section (changed to the '09, it handles way better in the deep snow), new '09 cooler, VE rear bumper kit, new A-arms, new 2011 seat...
What I already had on the sled is... BDX Diamond Drive Lite, SLP pipe, Y pipe, can, 2.25" Powder Claw, rage cage, 3" handle bar riser, boonie box, koso EGT gauges.... the cat needs to breathe so I did Moflow intake vents and Frogskins on the hood.
Thats the jest of the whole thing. I think the Cats are great, but for us to ride the cats like the boys, we definitely have to make sure it is set up right for us.