Bob,
From my experience, underhood black that I mentioned is different sheen paint and different part # than chassis black that Jeff mentioned. It seems that in your post you're wanting to use a rattle can since you mentioned Krylon. If that's the case, Eastwood does carry several different satin/semi black paints that I have used for years with great results and have had great results in the judging of MCA with the underhood black.
Duplicolor also carries semi gloss that is also exceptional to use in the engine compartment area for the rattle can user. Vendors also carry several different brands of engine compartment black.
You be the judge and use what works for you.
Good Luck with your project.
-Rich