Are you planning on painting the engine yourself? If so, you might want to tell them not to paint it. Most of them are engine builders, but not detail painters. They worry about flash rust after cleaning it.
I don't worry about that, since I always treat mine with Ospho, wait a day, wipe any residue (byproduct of the chemical reaction) with a rag soaked in Ospho (works as a solvent and doesn't cause any more reaction to the metal), wipe with auto paint thinner and wipe clean with a clean rag, prime with extreme heat engine primer, and paint with engine enamel.
Carl
