Jay, Adam's got it. none of them were painted from the factory...
for re-finishing...
the cleaning effect of medium glass beads provides a factory finish....only the outside as glass bead media gets trapped in micro pores. best practice is to ultrasonic clean post glass bead media blasting. if no ultra sonic then rinse, rinse, and rinse again will be fine since only the outside was done in the blast cabinet. not a problem if you do wet media blasting with glass beads. brake cleaner, stoddard solvent, or jet wash will take care of oil residue on inside. tape-off the engine serial # label to preserve it. unsure if soft heat from hair dryer will soften 37 year old dried out adhesive to permit safe removal for re-installation.