Did leaded gas wreck an unleaded eng performance?

[71PA_Highboy]

Leaded gas will plug the catalytic converter.

r/

eric

[george worley]

If it didn't have a catalytic converter it wouldn't hurt it.

[TNIceWolf]

The lead was added to the gas in the early engines to sort of cushion the valve face coming into contact with the softer cast iron valve seat in the head. Thats why the unleaded engines had to have harder seats...........and why hardened seats are recommended in any older engine rebuild now. So I myself cant see how it could cause any problem there.

[michael69]

Yea,as long as he took off catalytic converter it would not have hurt it. My dad would buy new trucks and cars and as soon as warranity was off so was converter along with knocking bigger hole in full filler neck for the Leaded gas.We never had a problem related to the leaded gas.