I can't remember where I read it so I can't verify it, but, I believe it said that the colors of the engines varied from green grey to orange and red. Back in the 50's when orders were short for green or grey engines, the order was filled with a orange engine supposedly destined for a passenger car. Also the color of the orange engines varied somewhat to a more red tint.
Like I said, I can't varify it without researching it through the books again, but it seemed logical to me that it could happen that way.
I also had a yellow engine but it was rebuilt. Some engine builders put their own colors on their rebuilt engines. I have seen lime green, yellow, black and blue instead of oem colors.

I read on another forum that

If you ordered the base V8 and a manual transmission, you got the 265, regardless of model.
If you ordered base V8 and automatic, you got a 2bbl 283, again regardless of model.
The first small blocks in 55-6 were red, and trucks yellow, and from 57-on orange.

Last edited by Builder; 04/07/2010 9:22 PM.