For Dodge:
The light duty 1" 19 spline input shaft used in 1992-93 was changed to 1 1/8" 10 spline in 1994.
1992-93 models had a coarse thread shift stub. This was replaced by a square stub that accepted a press on shift lever for 1994-1997. A metric threaded shift stub was introduced for 1998.
1992-1996 had an interlock mechanism built into the 1-2 syncro to prevent high speed downshifts into 1st or second gear. This feature was dropped during the 1996 model year
In 1997, New Venture changed the design of reverse gear from a dual plane to a single plane. The reverse gear ratio was changed from 5.61:1 to 5.04:1.
For 1998, the shift tower and shift handle were redesigned. 2WD models no longer had a speedometer drive (the speedo works off the rear axle). 4x4 tailshaft housings were changed to eliminate mountings for the transfer case shift lever. Also, with HD models, the mainshaft nut was redesigned late in 1998. This change first showed up on transmissions with an AD suffix on the Dodge part number (ex: 52108131AD)
For GM:
1992-1994 transmissions had a wider gear ratio with 1st gear being 6.34-1. Starting in 1995, the 1st gear ratio was changed to 5.61-1.
1992-1998 models did not have a synchronized reverse gear. A synchronized reverse was introduced for the 1999 model year
1992-93 models had an interlock mechanism built into the 1-2 syncro to prevent high speed downshifts into 1st or second gear. This feature was dropped for 1994 according to our GM parts book, however we have found them on some 1994 transmissions.
1992-1995 transmissions had a bellhousing bolt pattern unique to GM. For 1996 and newer transmissions, GM uses the Dodge bolt pattern.
In 1997, New Venture changed the design of reverse gear from a dual plane to a single plane. The reverse gear ratio was changed from 5.61:1 to 5.04:1