oem, I'm thinking the same thing. I ran around after work and did a bit of tire shopping, kinda settling on some Toyo 225/70R 15s all the way around (skinny white walls).
I was thinking of trying to stagger big rear/small front but there's not many options that keep the same tire/tread w/white walls that make sense. They did have the same tire in a 235/75R 15 but it was actually a smidge narrower (9.0 vs 9.1" section width) than the front 225/70R 15?? The taller sidewall didn't look quite right either
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Anyway, kept coming back to the 225/70R 15s all the way around as making the most sense (want to keep the stock wheels) and keeping fairly close to that stocker look.