Stock, there is no advance of the flywheel. The keyway on the crank and the keyway on the flywheel line up (with a key installed). Jugs do not come off. You port the ports, not the valves. Use a die grinder or a dremel tool. Don't go crazy, just smooth out any rough edges. The exhaust comes out the exhaust ports (not sure what your asking there). If anything, you don't want to deck the head. Just check it for warp. If required I would only take off enough to "true" the surface and no more.