themoose: Are you sure that engine came out of a RC10GT?? I race a Gt onroad and I never new a sg shaft would work on a GT. I use sg shaft engines on a GT with NTC3 clutch stuff,but it takes special engine mounts and a lot of trick work to make it work. All GT's I know of use standard crankshaft engines, no matter if its a RTR, Team or what ever. I thought all s/g shaft engines were the same, a extra shim or 2 maybe needed for spacing, but that's about it. Thread size I thought was all the same also.