Engine paint

I like the Rustoleum 500 F engine spray paints since you can spray at any angle. I used their primer first. I painted my block in the car when the timing cover, oil pan, and intake were off. I cleaned first with gasoline, alcohol, and steel brushes. Hasn't been long enough to tell how it will hold up. I used red on my 65 273, which was close to the existing paint (factory?). I used clear on aluminum parts to limit corrosion (timing cover, water pump, intake, valve covers). I even painted the inside of my new timing cover since my old one was pitted.

I personally think orange looks a bit cartoonish, but since mother Mopar used that in the 70's, if you want to be correct do it. To be "correct", you also bolt on everything first (exc. distributor & pulleys) and paint it all. The factory did that to be fast. It seems a little like people trying to reproduce the trunk splatter and torsion bar drips like the factory. Might win points at a show, but otherwise kind of silly.

You might also look at Rust Destroyer as a primer. It claims 800 F, converts rust, and etches bare metal. Comes in quarts (~$22) and spray cans (~$12). I used it on other parts in the engine. Might have used on the block too, I forget. I used to get at Ace, but had to go to a specialty paint shop for quarts last time. I recall Ace still has the spray cans. Home Depot used to, but couldn't find a few months ago.