I believe the 1953 and later clutch gear had another row of needle bearings, this had a profound effect on the popping out of high gear problem. This could be retro'd into older cases but you need to replace the mainshaft to a 1953 or later and I believe add a spacer.


1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration