350x uses the most popular bearing around as long as your carrier is stock.
Same bearing as 300ex 400ex 250r etc...any decent atv shop should have them in stock for around 50-60 for the whole kit. You can also get them from napa. Bearing number 6908-2rs. You may be able to re use the seals if they are not torn up. Sounds like they may need replaced if the axle is too loose like you say.
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