Try these two people. Let them know what you want, and I'm sure they can tell you what would need to happen.
Greg Ducato at Phoenix Transmissions out in Weatherford. I have not personally used their service but know people who have for their Mopar transmissions.
http://phoenixtrans.com/
Or Mike Miller of Miller Performance in Haltom City. Mike has done a good bit of work for me on my Dart, and knows his Mopar stuff. He was going to build my 904 for me until I changed course and had him install an A-518 OD in the car instead.
Miller Performance Home Page