My idea of original is a vehicle that hasn't been modified with non factory/dealer items such as modern oil filters, modern performance engine parts, and modern anything else that was meant to be replaced every few thousand miles. It's different to me when you change out the engine, tranny, and rear end to something else, that's basically the heart of "original." Most anything else that can be replaced affects originality too. Some things you just can't help to replace because these were built to be used and be used hard. I guess it all depends on your idea of original.
The actual original is when the truck is done with at the assembly line, after that it's never going to be exactly as it was.
