Hardened Valve Seats or Not?

stainless valves are a non-issue, its the seats that get worn. I say run it until you start getting some issues, then rebuild them, check that..REPLACE them with some post leaded gas heads. Installing hard seats in early heads is more expensive than just buying some hardened 302 pulls. Youll see the effects much sooner with mechanical rockers as you can gauge the valve sink over the preload.