This is the best paint (I've found) for Shovelhead and Sportster cylinders, cast iron heads . . . Anything you want satin black. It's perfect. Not too flat, not too gloss. It looks great and holds up very well. I paint head bolts with it too, then you can 'touch-up' after you torque them (same paint as the heads or cylinders).
Cures fully after running the engine. Smells terrible ! Wear a mask . . . clean the spray tip after use.