Perhaps my opinions should be kept to myself, but this one defies intelligent
explanation. With friends like this who needs enemies
The only caveat to using a 727 is that its bell housing must be for an AMC engine. Someone, please feel free to correct me if I'm wrong, but I'm thinking it doesn't matter if it's from a V8 or a six. If your 904 is a lockup you may have problems finding a similarly-equipped 727. Additionally, Eagles were originally equipped with a 998 transmission...a 727 case with 904 internals. Has someone changed out the transmission?
Your replacement transmission must also accept the transfer case. If it has a tail shaft you will need to do some work on it before it goes in. Perhaps the output end of your existing transmission can provide you with the necessary parts and you can save some coin.
Good luck, and please keep us posted.