Oh yeah, Dennis I forgot to mention......have some of those people arguing with you put their money where their mouth is. Bet them $10.
Then prove it. Keep a copy of the 1966 Chevelle dealer brochure (costs $10 on E-Bay) under your floor mat.
Maybe also bet them that they can't name all the variations that your car came in that year.
Take the $10 each time, buy beer, sit back and laugh at them.

opcorn: