I just located what might be a true 1969 big block SS Chevelle that has been sitting untouched for many years. I will have another chance to look this car over the week of Thanksgiving, and I hope to finally meet the owner and discuss its availability. If things go well, I'll be a frequent poster, as I'm a complete rookie in the land of Chevelles. Hopefully, my 25 years of playing with Camaros will help a bit.

WELCOME aboard!! Starting in 1969 the SS was not a separate model but an option package and the VIN nor Cowl tag will tell you if it left the factory as an SS. Only original paperwork, POP or build sheet can verify. One exception to the above is if it was built in Canada. Go here for more info on id'ing an SS.
http://www.chevelles.com/shop/ss_ident.html