When I measured with a string from the fenders, it took +28mm to be flush with the fenders. Therefore going to a 9" wheel (1" extra on the inside and 1" on the outside) at stock offset will get you very close. Then you have to select a tire that is also appropriately sized.
Further supporting my research was this post from
@ziggi testing 20×9 +35.
Nice setup! Those are some of the biggest diameter tires I've seen, at 29.5". Any rubbing? So far nothing. Only drove home from the shop with full load of my 20s in the back. Shouldn’t have any clearance issues from my understanding.
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