CoastalTony: Man, I've got more questions for ya, as I have found out this weekend I can't race there with a .21 engine, so I've thought about the O.S. 15 CV-XR, since you run an O.S. 15Max on yours (truck), could you please tell me where you get all the mounting hardware & linkages or do you still use the stock stuff??????? I was then thinking if I get that engine to install the KHB E-Z start system, which is a direct fit for pull start engines to be used with the stock Traxxas E-Z starter!!! Thier web site is www.khbracing.com