Well, Wade never chimed in, so I just went with the single speed tranny and steel pinion that's a replacement for the "Shockwave" buggy.. Looks like it should drop right in to the Tornado S30.. We shall see! Not sure when I'll put it in, but I had to order some new dogbones and figured I'd get it all at the same time.. Oh, just an FYI, Kurt at Unlimited ********* is flat out awesome at filling orders and helping hiscustomers who have Redcat Racing products!! (As well as all the other products he sells too, Im sure) But he's been great to do biz with, gettingparts for my Tornado (parts shipped within acouple hrs of ordering)and helping me out with extra little tips and tricks!! Thanks again Kurt, if you read this!!