Yesterday I replaced the factory stock (38 tooth) spur gear with a (36 tooth) gear. I stayed with the factory stock (14 tooth)clutch bell.I reinstalled the 3.3 onto my truck, and followed the gear meshing procedure as explained on Traxxas's "support" section on its website. I did not replace the slipper clutch shoes or the clutch plate as they have neither severe wear nor visible damage. I tightened down the clutch nut in 1/8 turn increments until the clutch engaged enough to make the truck move under throttle. I made sure to NOT overtighten the clutch.....The problem I am having is when I apply throttle 1/4-1/2 or more throttle, the engine RPMs are notably higher in relation to forward speed than before the replacement of the spur gear. I checked to see if I could move the engine closer to the spur gear, and there is little if any room to adjust. I did the paper trick when setting the gear-mesh. The unusual RPMs sound kept me from throttling into second gear. Any tips/tricks/ or advice is greatly appreciated.