I believe 4/1 in the front is the best choice for handling. 3/5 for the rear is a good choice. My R is a duner only so I can't give advice for mx, but 4/1 front and 3/5 rear is what I have. I also have +3+1 front A-Arms and a +4 lonestar axle. Add in the ccp steering stabilizer and it is a very good handling machine. Now I am just waiting on a set of axis shocks!
Loren