Question about Clutch Springs

Friend just purchased mint 09 Ranger 700 HD and was wanting to know about belt life for this UTV and asking about stronger spring for the clutch system? Which spring would be upgraded the primary or secondary spring or both? I've also looked on parts list and saw that on some they call for same belt as the RZR 321113 and on other listing part 3211077 and 3211118.
Anyways i need to know mostly about springs and where to find different strength and color springs. Would they make much difference and even on our RZR's.

CVT clutch tuning is an endless conversation and is a science of its own. EPI, Speedwerx, HPD, Quad Shop Customs, Dalton all have various springs. They are usually around $25 a piece. I think the 09 Rangers are equipped with the Team 3 Roller Secondary, which is one of the best secondary clutches out there for a Polaris. This is the same clutch that is used in the 900XP and the 08, 09 RZR 800s (they went to a fixxed helix starting in late 09). Just remember if you go to a stiffer spring in the secondary, your gonna loose some top end and your upshift will slowdown (staying in a lower gear longer, which is good for big tires), but your backshift will be quicker (getting back on the throttle out of a turn). And putting a stiffer spring in the primary will raise your rpm engagement, which will give you a better launch, but your takeoff will not be very smooth (kind of like dumping the clutch on a straight gear with the gas pedal to the floor). Just my opinion, I think it takes a little bit more than just springs to get a clutch working the way you want it to. I good set of aggressive primary weights to go along with the springs is the way to go. I have tried various clutch components on my 500 Sportsman and I've learned that it takes patience, lots of reading and some $$$ to get one tuned the way you want it to. After about 3 sets of weights and a pile of springs, I finally got my 500 running the way I want it too.