I used Duplicolor engine paint.....so far I like it....I used it on the transmission, engine, starter/generator and the oil filter canister....so far so good..it's supposed to withstand 500* which might be a little optimistic...but it has withstood the oil and water spills...
Eastwood sells a two-part epoxy that has a special 2 part aerosol can...expensive though
As always two part auto paint with a hardener would probably be best if you have the equipment......