Best bet? Don't clean it, list it on Ebay with the specifics and see what it brings. I would order the PHS www.PHS-online.com and verify the drivetrain.
Verifying the original drivetrain (engine, trans, rear) will bring you 30-50% more than a non original engine and trans. The rear is not car specific (no VIN) but can be located with effort.
A correct original 400 3 speed is pretty uncommon. Rare? somewhat, but not sesirable. Most 3 speeds found their way out through damage or attrition for favor of a 4 speed.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
