The original paint that has been used for block and head was a paint called gliptall spelled wrong been long time you could buy this from Granger I now use insulating EPOXY coating thermal rated class F flexible, resilient finish this EPOXY is fast drying
has excellent moisture, oil alkali, and chemical resistance Leaves a flexible finish this is what is used on Electoral motor windings , The reason I use it is to seal any un seen particle left from clean or pyre cleaning down glass bead mag check etc the first coat seals the rust and any thing not cleaned between block or head surface, The second coat is used after machine work has been (cleaned ), to seal any left particles then a third coat is used before,
final assemble your heads have this done to them all my heads are cleaned and painted three times , This Epoxy is used on field coils, exposed metal, windings, taped coils frayed insulation,pitted motor winding, bus bars, collector rings, transformers armatures, and commutator ends, recommended for extreme moisture and oils, I use this on all my heads and block coast over $ 6.00 per can No Rust, helps oil drain down to helps to stop
slug in heads to build up . and rust from ex reversion