I think the only way I'd be able to get the existing oxidation layer off is with acid which seems like overkill. I'm just going to spray down the whole thing with Simple Green and give it a good blast with my garden hose nozzle, repeat a few times, carefully spray the spot with brake cleaner (top side of manifold is painted) then dry it with compressed air. I'm going to build up a decent-sized glob of JB then file it down flush with the sealing surface, I figure if it withstands that without coming off it should hold up while on the engine.
@74Scooter I think Right Stuff is what I used last time, it almost worked too well lol... It was a bear getting the manifold to release especially toward the rear of the engine, I'm not looking forward to scraping all the residual stuff off. I might go back to Permatex Ultra Black tbh, never had an issue with that sealing except on this engine which isn't really the fault of the sealant itself anyway.
