That corrosion may not seal well unless you hone it out Corrosion like that is not uncommon on motors that have sat a lot in high humidity area, it, the moisture condensation, gets into the cylinders through the exhaust valves Let us know what you do and he results, that will help others on here also
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)