Denny,
Here's the PPG # I had mixed, DCC 36304, Dark Gray. I thought the same thing when I first got the paint, looks awfully dark. But once you spray the entire assembly and get it in the sun it does "lighten up" a bit. Just tricks the eyes play on you. Same thing goes for the chips in those paint books, once you see the painted vehicle, it doesn't usually look close to the same shade as the chip. Like I've said before, as far as the gray, you're talking a time span of about 30 years that Chevy used that color, so I don't think you'll find a definitive, this is exact, answer. I do know that all the NOS engine parts I've come across are a dark shade of gray, much darker than the Bill Hirsch paint.
As far as what's painted, it helps to have a sort of "manufacturing plant mentality". The question comes up often and I think back to the years I spent working at a Caterpillar plant. Usually everything that can be assembled before the trip through the paint booth is. As far as the engines, about the only things that aren't painted gray are the small bolt on items, distributor, generator, starter, carb, fan blade, and draft tube. All the manifolds, bellhousing, gasket edges, valve cover acorn nuts, oil filler cap, and even the adjusting bracket for the generator since it's bolted on with one of the water pump bolts, were gray. Manufactures aren't into "detail painting".
Bob
