The commonly accepted Chevy gray for engines is being sold by
The Filling Station. Different computers and monitors will show slightly different colors. I see from getting the link that it's gotten pretty pricey but I guess all car paint is expensive these days. Below are a couple of pics of my 216 in it's new livery following it's rebuild. It's important to keep in mind that Chevy didn't buy one master batch of engine paint from one jobber. Batches were mixed by different jobbers when and where they were needed so hues will vary. Anything close will be OK.