After pressure-washing it several times, I basically hosed the engine down with paint, except the intake & plenum. I didn't want to break those seals, or risk breaking those bolts. Same for the exhaust manifolds - they're not leaking, so no reason to risk it. The spark plugs are being replaced anyway. There was never any indication that the rear main was leaking, so I didn't mess with it, but I did threadlock the flexplate bolts.