Engine Paint

Do not paint the inside with regular paint, it can flake and peel causing it to end up in all kinds of places you don't want it. You need special paint for the inside of the motor. Painting the valley helps aid in oil drain back to the pan. I myself do not paint them because of the fear of the paint coming loose and killing a motor. I do debur the valley and the inside of casting flash and smooth the valley with a flap wheel on a die grinder to help with the drain back. But mopars have a pretty smooth casting for the most part so as is would be fine also.