emichura

I have a Jayco Mini with an 1985 Chevy 5.7 V8 (VIN Code M) engine with 37K miles. The manual calls for leaded fuel. The Light Duty Emission version must burn unleaded -- I assume because it has a catalytic converter. Can I burn unleaded gas in my engine? Are they the same engines with only different emission controls? Do I need to worry about valve seat recession?