Google up "glyptal paint" and you can read all you want on it.
I read a quick article by some hot rod enthusiasts and the consensus was it's not worth it, especially for used block where there are greater adhesion problems. Of course your mileage may vary : )
http://www.jalopyjournal.com/forum/threads/is-glyptal-engine-paint-worth-the-bother.644312/
Just use Cat yellow primer.
I use red insulating varnish on the insides of the engines I rebuild. It dries nice and hard and stands up to oils well and doesn't wash out when parts are run through a hot tank. This is the same stuff that is found on electric motors to seal the windings.
Mike
Thanks guys for your input my only real concerns is rust when the machine sits for a few months but i guess oil on the insides might prevent that from happening