I have a factory 74 D100 with 440, I haven't been able to find any production figures but I know there wasn't very many built, generally you find the 440's more plentiful in the 3/4 tons and 1 tons as compared to 1/2 tons. Mine also has the tool box on the side and my door is in pretty rough shape but I did manage to find a really nice one at my local Pic a Part last year. I have always liked the looks and all the different options and packages that came on the 70's Dodge Pickups and Ramchargers and I see now that LMC Truck is starting to have alot of parts available now for the older Dodges. Good deal!!