Question about gear swap

I was getting ready to press on the pinion bearing onto my replacement gear set (3.23) and noticed on the old set of gears (2.74) what appeared to be a thick washer below the pinion bearing. I pulled the bearing off of the 2.74 set and sure enough there was a thick washer probably about 1/8" thick, sorry didnt mesure it exactly.

I dont remember this washer being on other gear sets Ive done. So curious if I reuse this washer on the 3.23's or just press the bearing tight to the pinion gear?

There was also a sleeve that sat on top of the lower pinion bearing, then the shims for the upper bearing. I dont recall this sleeve on other sets I've seen either. Do I transfer that to the new pinion? If you need pics of these things I can get them and attach them.