they paint the insides of most heavy duty diesel engines and heads I never saw any signs of flaking or discoloring of the paint / most mopar engines used in circle track need extra help getting oil back to the pump ,the oil gets trapped in the heads and wont drain back. some put extra drain lines in the valve covers or drill thru the head and back to the pan. going around short tracks with steep banking traps oil in the v covers ,and you have unexpected rod failure
