To be honest your far better off running it with a carb rather than a exhaust throttle. Exhaust throttles are messy and only efficient running wide open. Are you planning on racing this motor or just playing around? An exhaust throttle will give you a few more rpms on the top end (as long as your pipe is setup properly) if you're concerned about the rod in your engine then an exhaust throttle is not the way to go. But if you really want one PM me and I probably have one that will work, if not I could make one.