there was a rumor circulating a few years back about one of the shipping companies having copies of old lading bills that gave option info...I was never able to confirm it...GM has data available for two groups of people...the Pontiac folks have the Pontiac Historical Society (PHS) which can document cars from the sixties forward. I have also read that GM Canada also has records for GM cars sold there...I am not aware of any source of info for non-Pontiac US cars..(hence the fact that there are more 435hp '67 Corvettes on the road today than Chevrolet ever built!!!)