A quick google search found this..take it for what it’s worth..
“I don't have my '91 era RV-4 wheel p/n handy, but for it, the following info is what I have.
The 'stock' tapered bearing set for Clevelands are 'precision' bearings. They are fairly pricey. From an old Matronics RV-list post:
I don't know whose P/Ns those are (maybe Van's), but from the Parker
Cleveland Parts List, I show the Cone Bearing as Cleveland P/N 214-00400 and the
Race (Cup) as Cleveland P/N 214-00300.
Some of us have found that in our personal experience, the following 'less precision' bearings fit the axle/wheel, and have given hundreds of hours of good service (links are to NAPA part #s, but they are Timken bearings):
The Timken #s are 08125 & 08231. You need two sets for each wheel.
You must make your own decision on whether to pay the premium for the higher precision versions (if you order the Cleveland p/n, you'll likely get Timken bearings; just the higher precision tolerance versions).”