This spring I repainted my Buick engine (avatar) using VHT Cast Iron color, really like the color and easy to keep clean.
I used Model A green on the six in my avatar. It's so dark, most people think it's black. Sure makes the shiny bits pop.
After chasing oil leaks on my flathead I'm thinking a nice shade of Valvoline would have been a good choice so it would just blend in. I'm even thinking about creating a dye for motor oil so it matches the garage floor. Go with the Grey