The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 1964 Chevrolet C10 4x4?

Please see link to 1960 Brochure which shows two frame designs - one for 4x2 and another for 4x4.
http://www.oldcarbrochures.com/stat...evrolet%20Pickups%20Brochure/image4.html
And I thought that design continued thru 1966, but I guess I was mistaken. See link
http://www.oldcarbrochures.com/stat...20Pickups%20Brochure%20(Rev)/image4.html
Since the 2WD and 4WD frames are essentially the same, then a C10 could be converted to 4X4 as others have suggested. Whether NAPCO or not I don't know, though I have read of some NAPCO trucks being built into the 70s. You could visit the NAPCO Facebook page for more info.