Can unleaded gas be used in a 1972 351 Cleveland engine?

Yes, unleaded gas can be used in a 1972 351 Cleveland engine, but it may require modifications to prevent potential engine damage due to lower octane levels. Originally designed for leaded fuel, older engines can benefit from the use of high-octane unleaded gas or adding an octane booster. Additionally, retrofitting the engine with hardened valve seats can help accommodate unleaded fuel without issues. Always consult a mechanic for specific recommendations on fuel and modifications.