I'm working on a 1957 261 that was originally yellow, consistent with Tim's post. If your engine was originally yellow, the date code should place it as a 1957 as that was a one year only color, but Chevy wasn't always precise about engine colors and would use what they had until it ran out from what I have read.
When I did some research about what shade of yellow to use, I found some posts elsewhere that stated that Old Caterpillar Yellow was a very close match.
I also discovered that Old Caterpillar Yellow has been discontinued by most paint manufacturers and replaced with New Caterpillar Yellow, which supposedly a different shade. I was able to find some Krylon Farm and Implement Old Caterpillar Yellow with a Google search, but it was very expensive and I was concerned that I'd never be able to find it again in the future if I needed touch-ups or had to paint a replacement part.
I ended up using Rustoleum Farm Equipment John Deere Yellow. It seems to be a close match to the yellow that I was able to uncover on the engine under several layers of Chevy orange paint. I like the look and can post pix if you want. I found the best price at Home Depot if ordered online with free shipping delivered to the store for me to pick up, $22.56 for a case of six cans.
http://www.homedepot.com/p/Rust-Ole...-Spray-Paint-Case-of-6-7443830/202058760I am colorblind, so I can't be a great judge of paint shades. My wife helped me.
Matt
