Survivor...?

I am not sure if this happens to everyone, but I typically get comments about both of my A-Bodies (1964 and 1966 Darts) that they are great survivors....which is typically a precurser to a comment like , "Dont you dare do anything to these...leave them just like they are today."

My question though is...what makes a car a survivor? I can guess it has to do with the original nature of the car, but are there specific rules about what this entails...X% original paint, etc...?

What can you do to a survivor without affecting its status as a "survivor"?

Does Headers (if I can find them...), dual exhaust, 4bbl carb and manifold detract from that status?

My 1966 is an all original car that has never been touched. I am dying to do the aformentioned modifications to it to add to the fun factor, but am I taking away from its value? If I keep all of the original parts, does that help?

Sorry if this is a crazy or ill-informed question, but I kind of feel like I want to make some modifications, but I do not want to end up loosing in the long run.

Thanks,
Clint
San Diego
http://members.cox.net/cschmucker/