If you use that engine with an M32 pipe from TSAI and kick up to a 15 or 16 tooth bell, I can say that you will have more speed than you can handle if you broke it in with a nice heat cycle and a couple rich tanks on the track. The pull start can still unwind slightly on any engine and with a buggy, there is no room or leeway. If it releases just alittle at the wrong time, like landing a jump, it's done. I would get the 333 oz. inch Hitec servo and the pipe. I have not seen any other breakage on the stock knuckles so cnc is up to your budget. Good luck and check some other threads for set up and the servo mod. Run your servo in the stand up position and if you turn the servo saver around to the out side and use a longer servo horn you can get more steering. Good luck with it and just to let you know, one of my race buddies runs the H7 and he gives every high zoot buggy a run for their money with the servo long arm and home made shock towers I made him from G10 fiberglass. He runs Jammin big bore shocks cause they are easier to adjust for him instead of shock clips and that is all he has changed. The stock shocks are fine but you should drill the rear shock piston with a 1/16 inch. bit in one hole and that will allow the car to fly flatter and not get kicked up in the rear on sharp bumps.