I put a 36T spur gear in and my OS 18TM in my REVO still wheelies just as bad as when I had the 38T spur. I bet I picked up another mph or 2 on the top end but it didn't keep my front end down one bit. Wheelies get alittle annoying after a while IMO. I think I'm gonna install the CD in my REVO. Hey Kliff, I already have FOC, so can I just buy the parts I need for the CD or do I have to buy the whole kit that Traxxas offers? How well does the CD work? Easy install? Any modifications?