We have finished testing our 912 bb for the Ski Doo G4. Kit comes with the following. Cylinders bored and ported. Rave valves machined. Powder Freaks Billet Head. Jaws pipe and ypipe. Pistons, gaskets, wrist pin brgs, and base gasket. Send in your cylinder and rave valves for machining. Dyno results are from our in house dyno. Testing done at 1850ft elevation. This dyno test is for high elevation 3000' + kit.