The MMC Detroit books will overlap to a small extent on some items as for as the inner fender bolts, hood hinge, trunk lid, etc. But as you delve deeper into the restoration, you will see differences in items like the headlight seals for a Belvedere are different than a Satellite and it just continues on and on.
As have mentioned above, four dour sedans and wagons can be a good source of documentation. The high performance cars back in the day were taking from the dealership lot and headers, intakes and cams were added within the first month of ownership. So at that point, the correct fasteners and bracket orientation has been lost forever.
I am very fortunate that I have had the opportunity to hunt through some very good salvage yards through the years and they can be a good source of documentation. Just need your camera or now your cell phone to snap a picture now of the different components. I have spent numerous days in junk yards pulling parts for the purpose of reproducing the parts and always make notes on certain aspects of the parts.
Finally, most car owners love to talk about their cars. Politely asking the owner to see certain details will almost always lead to more information that will be beneficial in your restoration. Being from a small community of being the only Mopar within a 30 mile radius, I have learned that you have to venture out to see the best of the best. For some people, it is not a possibility, but now days, a three hour drive to most metropolitan areas is not a big deal and will allow most the opportunity to see different cars, techniques and levels of restorations. Enjoy the hunt as it can be a good ride.
