I have most of the notable books on E bodies and I have to say that none of them are what you could rely on to be a truly definitive guide on all things E body. The MMC book is great for fasteners overall but does have some gaps, especially in later cars (73-74). There really isn't any guide per se to restoring or building one other than the factory manual. I am sure there is someone out there capable of writing a book but the problem here is that the cars had variations when new, panel fitment was not great, and cars from one plant vary from another plant. Thus, any book would be riff with controversy and argument not to mention it would steal some of the "secret sauce" that restorers love to hold onto in order to command big money.
It really depends on what you are trying to accomplish, a restoration, a daily driver, a hot rod or a restomod; each one of these has a different intent and thus would approach things in a different manner. A FSM, forums, and your own research are the best things to use and rely on. The one thing you should always have in the back of your mind is that when it comes to Mopar, never say never to almost anything. Mopar built cars at a rapid pace back in the 70's and there are many instances of things being put onto cars or cars built a certain way that should not have been. Do not believe the "experts" wholesale, meaning trust but verify. There are many self proclaimed experts in the Mopar world and most if not all have proven to be incorrect from time to time; a good guy will admit it whereas many others will not.
There is a certain amount of what I would call "extrapolation" in the hobby, meaning that while Mopar perhaps did not call out or identify some things (such as what comes in specific packages), looking at factory documents, pictures, survivor cars, etc. leads the hobby to believe that certain things existed in a specific way. That said, many times these "truths" are found to be incorrect in certain instances which throws doubt onto everything else. Point in case, some years ago someone was talking about how you could not get a specific steering wheel in a car (it was a colored steering wheel as I recall), this "expert" claimed it was not possible period. Well about 5 minutes later someone produced a picture of a car when the car was brand new on the lot with that exact steering wheel.
You have to remember that many things were going on back in the 70's and Mopar was known for 2 distinct things as it relates to the modern day; first is that they would put almost anything on a car if you were willing to pay for it, second is that during assembly they used whatever they had available to keep the cars moving. They had little to no regard to consistency. There are many cases where a build sheet exists yet it does not accurately portray what the car has or was built with. On top of all of this, Mopar did not keep or retain good records (lots of rumor here along with some degree of conspiracy) so the net result is that are many ways to build a car today that may in fact be right (reference a restoration).
Hey, you live in a golden age with the internet, with a few key strokes you can look at pictures of survivor cars, talk to people who have been working on them for decades, etc. I was buying and driving these cars when they were less than 10 years old, but I can say now that I did not pay any attention to many of the things that are now so important (thats sarcasm). Back in the day, we did not give a crap about Hemi this or that, we bought what we could find and made it into what we wanted because every single one of these cars started life EXACTLY the same, an empty shell that was then turned into whatever the order was for. The only difference between a slant 6 car and a Hemi car is what has been welded or bolted onto the shell.
