mike, razerthon is saying that you should us the collet from the HPI savage, if you look at a-mains site I'm sure that you will be able to find it. Regarding shimming of the flywheel this is a pretty basic thing that you are going to have to do with any clutch or engine. Basically you use the small shims (thin washers) to move the flywheel forward or backwards. This is done to move the flywheel away from the carburetor, to center the flywheel in the starter wheel cut out in the chassis, and also to adjust the positioning forward/backwards of the clutch bell. Again this is not really engine specific, you are going to have to shim these things on every engine/car. OFNA makes a nice shim kit which I'm sure that A-main also stocks. If not just about every hobby shop will have a clutch shim kit in stock. Hope this helps!

Regards,

Ron