My first set of tires were a set of 28x10x12 Zillas on stock aluminum wheels which were 12x6 front and 12x8 rear. They worked fine, but were a little more "balooned" in the front due to being on a narrower wheel. Placing same size tires on the stock wheels is very common, due to the cheaper cost of not having to bug a set of wheels.
What size tire you looking at?
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