I found out that most places have the bearing positions flipped. So Rock will say it is for the left side when it is for the right. Because the M200 is normally a rear diff. Just FYI.

Passenger side: XAB32010XM
Driver side: LM603049

Those are the actual stampings on the inner race. So make sure you get a set.... for example, driver side is LM603049/LM603011 with the 11 being the race itself. Some places do sell them separately.

 

Rock lists 3 different bearings for the front M200 diff, National A64 "front outer" $31.79
National A36 "front right" $13.03
National 32010X "front left" $24.79

Or I can get a whole kit (*something 007* same part number as AB) from heritage for $114 plus ~$120 shipping plus whatever tariffs they might apply. (they do offer free shipping on larger orders)
I already have all the seals so ordering from Rock seems like the best option, but I want the same exact bearings to avoid shimming.
Got 2 front diffs on the table now, cost me about $300 plus 5 hours of driving for both and I still don't have anything worth installing

 

A64 is the "kit number" for pinion bearing. A36 is the "kit number" assigned to a bearing and race combo and Google shows it cross references to the Timken for driver side carrier bearing. The other side will be BCA/NTN for me because I already bought that one also but its dimensions are the same as the Timken, unlike the National.

I paid $46 for my driver side Timken, a lot more than the National A36 I already bought..... (EDIT, my bad it was $23, the passenger side one would have been $46 for which I am using the BCA/NTN instead.

That really sucks about the two diffs. I maybe lucked out with mine but it was a mess to get one. Are you searching via car-part.com? It is the only way I look for used local parts. There are diff around me in plenty for $100 or less.

 

Pinion bearing is Timken NP310800, FYI.

 

Measurement notes on carrier bearings:

Driver side:National 21.60, total package
Timken 20.00, total package

Timken new race, 15mm
Timken original old race, 15mm

National race, 16.65

These next measurement are not very accurate cause of the bearing cage interfering:
Nationa body only (no race), 20.2
Tim Ken body only (no race), 20

Pass side:

Both BCA/NTN and old Timken race measure 15.45mm


And today I installed both races. Only thing to do next is clean up the gears really well and paint em to check the interface and check the backlash which value I am still not sure of.

The pinion bearing on mine, like I said before, seems excellent and I had no plans to replace anyway. Originally they would "stick", it took some slight force to get them to rotate then they spun smooth and fine. Once unloaded with no input installed there was actually play in them (that is when I cleaned em up). I marked the nut and pinion shaft and after getting this close to my mark I decided to stop for now and checked the force needed to rotate the shaft. Which no longer sticks at all, just spins smooth. I am getting about 3.6 lbs on the fish scale which is as far as I know pretty good. But I still need to see if I can find a true and proper value. But based on two sources who have done pinion seal replacement with the diff still installed in vehicle, that is about the proper force.

 

I opened SKF needle bearing today and it's a Koyo inside! not pressing anything yet, gonna order the bearings below and start cleaning up and removing the bearings

This is what I found on Rock
Timken set someone mentioned on facebook, National below was listed for M200
Timken SET37 $15.80 (don't know which side) consists of LM603011 and LM603049
Timken Race NP312191 $11.85 and cone NP310800 $16.84 on the other side
or National A36, $13.03 National A64 $31.79, National 32010X $24.97, no idea which is which

Looking at photos National A64 consists of Timken NP312191 and NP310800

 

This is pretty confusing:
National A64 shows picture of race stamped Timken 312191 and cone Timken 310800
Timken 312191 shows a pic with stamp LM48510
Timken 310800 shows LM48548