In 1965 I purchased a new 1965 Custom Cab C20 with a 283 V8 and a power-glide trans, the rear end had 456. gearing. Only engine options in 65 was the 283 V8, 230 6cyln and the 292. I very clearly recall that the 283 was gray, the 230 was gray and the 292 was green.
Chevy came out with the 327 V8, TH 400 trans option in the '66 trucks.. The truck 327 V8 was Chevy orange through 1967, the 350 V8 came out in the trucks.
I'm just finishing up the rebuilding of a '37 GMC T14 1/2 ton. We put a '72 292 6 cyln in the truck, painted it Chevy gray. The person that rebuilt the 292 painted it Chevy Orange because that is what he thought a Chevy engine should be.
Before the factories started to use any engine in any car, the engine color told the mechanic's on the line what the engine was, they did not have computers to do their thinking for them.
