slayte,
Good luck on agreement and on "definitive" answer(s).
Chevy Duty is selling the wrong color paint for a Chevrolet truck engine, unless it is Blue-Gray.
I have used Jim Carter's gray (too bad they did not give me correcxt information on how to thin it).
Blue was used for 235 car engines (Blue Flame Six) from at least 1954 onwards (also, maybe on the car engine in 1953 if it equippped with Powerglide transmission). Blue was also the color of 235s from '54 onwards on the Panel Delivery engines.
Truck engines were gray. It is not clear if the gray color changed a shade in 1954 or between the 216 and 235.
Shops often used orange after 55 because that was the V8 color.
Here is a webpage on this matter: Note that it says your engine would be green (maybe - was it a Loadmaster or a Thriftmaster - I read the info below as being confusing for '57 which matches '56 which matches '55, except for Thrifmaster or Thriftmaster Special).
http://www.danroy.com/tech01.html Note the blue-gray versus gray (versus green) for different year 235 truck engines.
Maybe there are simply no definitive answers to some questions.
Best wishes,
Tim