8&3/4 gears installation kit advice needed

Just a gear change? No current issues with chuck? You could get away with pinion bearing, shims and pinion seal but Kits aren't much, but I do see two different carrier bearing sizes. Not sure how to determine which you have? Maybe housing #??? Possibly axle or pinion spline count? Hopefully someone will assist.
More Information for MOTIVE GEAR R875RM
More Information for MOTIVE GEAR R875RMA