If you wan to clean out the oil gallys.. You can pay a garage to flush the block.. Or buy something that you run in the oil... But drain the oil right away. The only time i would suggest to use seafoam... Is drop a few teaspoons into the spark plug holes enough to seep into the rings. Let it sit over night and then crank it over a few times without the plugs... Then start it up and let it smoke for a half hour. I use Marvel mystery oil myself. If you really clean you rings and valves...and keep em clean. Run water injection. It will steam everything.