Doc, I did a significant amount of research before I painted the 235 in my 54 3100. I came to the same conclusion. There were specific paint codes for everything except the engines. Another fact was the 235 was painted blue if it was going into a car and grey if it was going into a truck. The grey was very similar between assembly plants but they all mixed their own engine paint and that led to slight variations. If I ever have to pull my fan blade I will have to consider painting it grey.
