Chevy orange was readily available in engine shops. It might have been used on any rebuilt engine.

What is the code that is pressed into the block just behind the distributor?
That is the Engine Serial Number and it might help to ID the engine (car or truck, and model/series of vehicle).

How did you ID the year - 1962?

Depending on the year, the truck high-pressure 235 might have been gray, blue gray, or even green (supposedly).