47 chevy, Some recommend haveing hardened seats put in to use unleaded gas, however many of us don't do anything except keep our engines well tuned, ignition and fuel air systems and drive reasonable with no adverse efects from the unleaded gasoline (87 octane), The engines are fairly low compression ratios and anyway leaded gasoline mainly prevented "fuel Knock" in higher compression engines. Some say that lead also cushioned the valface to seat contact and burned cooler, they just haven't convinced me, investigate and weigh all the facts, I would rather spend my money on other parts like a good exhaust system or a complete brake job.
