904 help
I performed my first 904 overhaul last year on the 66 with great results and installed a Transgo shift improver kit. One of the issues it claims to resolve is front bushing and seal burn up.
I used their SK
®TFSC kit and I really like the shift firmness. I'm not a transmission expert by any means, but maybe someone else here can chime in on this one. The Transgo site link for the Mopar stuff is below.
http://www.transgo.com/sk_dodge.php