Well I did this to my sled and what I have found to work good so far for mine:
Jetting:
Stock needle position
Fuel Screw 1.5 turns out
470 Main
Clutching:
10-64 gram Weights
Black/Green Spring
Assault Secondary Spring (Black I think)
Can't remember what helix but it needs the same setup for the Assault. This is for a 144" track.
My Egts are around 1050* at WOT so there is still some room for leaning it out, but I like to do long WOT pulls when climbing or sidehilling. Rpms are right at 8300rpms and that is where this motor make the peak HP. I have the Dmax porting, twin pipes and shaved head to run 100 octane.
Hope this helps, if you need some help, let me know.