If you sell it as a pickup truck, the buyer probably won't care. If you plan on selling it as a pretty vehicle properly restored, then it could well matter to a potential buyer.
By now, almost every square pickup is a mix of OEM, aftermarket new, and salvage used parts.
The rare few that claim to be all original are in this price range:
http://67-72chevytrucks.com/vboard/s...d.php?t=797985