Those numbers are way too low. Actually... looking at your #'s... those appear to be the approximate production numbers for the 8' fleetside C10's for their respective years. Check this out:
http://67-72chevytrucks.com/vboard/s...d.php?t=104816
And that's only chevrolet. GMC numbers were lost in a plant fire or something...
I added them all up one time... I think there was 2.5+ million 67-72 Chevrolets and whatever GMC made? So probably over 3 million trucks.