833 shift rod seal mod's.

Hey fellas, a while back I swear I had found a company that would modify your stock a833 side cover. They bored it and instead of using the single O-ring to seal the gear oil in I thought it was bored for a better lip seal. Also though they installed needle bearings for more support. Ive seen a few places that do this for the chevy 4-speeds but for the life of me cannot find the name of the place that did this for mopar a833's. Anyone had this done before? I ask because my 3-4 shift shift rod seal is starting to leak. I replaced the o-rings when I had it apart a few years back. Now leak is started. Noticed it has a few thousand's more in/out movement than my 1-2 shift rod when pulling in & out on the the levers bolted down to them. Any thoughts? Thanks guys. I made a about a .015 shim and placed in between the shift lever & the side cover to eliminating the in/out movement. That has seems to help but haven't gotten long enough drive in to really warm up the oil in it.