Another guy that knows his shit is Justin Whitey Folk he races at humbolt all the time multi track champion Dirtworks is 417 465 2410 Yeoman Racing Engines is 629 783 2662 again if you call dirtworks ask for Andy hes the smartest of the group and John Yeoman is my engine builder just tell em Tim North Jr. sent you there way. Good Luck and let me know if you need anything else!