My fave bike with 11spd 105 drive train has been shifting sloppily lately. (Rear Derail) I assumed at first it might be grit in the cables (internal routing). I also thought it might have something to do with cable tension. Since it was really busy out there today (Sunday tourists and a car show) I decided to give the old gal a thorough cleaning, lube, and adjust everything. Discovered the upper jockey wheel was sloppy as all get out. Bottom one in good shape. Dug into my parts bins and came up with a likely candidate from an old 8spd derailleur. Shimano in relatively good condition. Discovered real quick that it's 1 mm wider made a huge difference when I shifted down to granny gear and the spokes scraped the DR. Luckily it was on the stand. So I swapped the bottom jockey with the wider one because there is more clearance for the bottom one and tried again. After some slight adjustments, it shifts smooth and crisp. Now, with all that background info, I am coming to my question. I noticed that there are slight differences between the 2 wheels with the top one having deeper teeth (11) which is now in the lower position. Since it works, do I still need to get a set that also has the differences and put them in the right positions, or can I just buy a pair of wheels (identical) and throw them on there. I plan to upgrade to sealed bearings on them, but not sure what else is important or relevant. All comments or bits of wisdom (regarding jockey wheels, not life) are appreciated. Thanks in advance and sorry for the long speech. Smokey.