Ok I'm running 22mm mikuni carb, K&N air filter, performance header, governor removed and an ARC Billet Rod on a real gx160. I was wondering what valve springs do you guys recommend and how essential would it be to get an alum. flywheel and with that automatic 4* timing advance from the new flywheel should anymore be filed off the key??? I just want to get the fullest out of my engine without loosing its reliability