Hey Word, You can get spring sets w/ heavy, med., and lite. The 5.5 rollers will give you more rev's and more time to top out, the liter clutch springs will give you a quicker lock up on the clutch. tunning these parts is a pain in the @##. I found setting the clutch first will make it eaiser to tell what the rollers are really doing. I read alot of posts on combos, and found too many varriables to use any combo out of the box. I did wind up w/ the heaviest malossi springs from the kit to get my rpm's into the technigas pipes power band. It took a little while to get used to 3000 rpm starts, but i get to 45 mph in 3-4 secs,58 4-5. On flat ground I will hit my rev. limit of 13,500 between 65-68 mph. Not too shabby for an "01 super fever. The only drawback in my setup is my Kenda rear tire. It's a 130x60-12. There is about 1/4" clearance when cold, but at top end the tire grows till it just starts to rub behind the engine. I'm looking for a stronger rear tire.