https://www.forabodiesonly.com/mopar/threads/who-builds-the-best-904.252218/#post-1970184389
The post quoted above is over 10 years old and I'm not speaking from personal experience, however Magoo's Automotive has been mentioned several times in the past both here and on other forums when someone asks about an AZ local who specializes in A727/904 transmissions. I'm not sure if John is still around or not, but attempting to give him a call certainly can't hurt.