Hi just purchase a 69 Mustang 302 engine. I believe I'm the third of forth owner of the car. I don't know, and I cannot find out, from previous owners, if the valve seat were change when the gas went from Leaded to unleaded. I know that if the valve seat were not change you can buy additive that you put in the gas along with the unleaded and I certainly willing to do that and that is the same as leaded gas.
My question is, if the valve seat has been change and I put some additive in with the unleaded will that be bad for the engine also
Has somebody have experience with that situation and could advise me.
Your co-operation in this matter is really appreciated.
Don