well, plug these numbers into offset calculator.
my rear wheels are 18x10+38 with 275/35/18, tucking about 3/8th of tire, fender is pulled 3/4th inch, 0 camber. Just off my head, you shouldn't have any problem fitting that with 35mm over fenders. Front's you'll need about 5mm spacer to clear the coilovers, because my 9.5+15's are about as dangerous as it gets. LOL and step down on the side wall there, because the 255/40's are going to be super tall.
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