The 28x9 et drag on a 15x8 wheel with 5.5 BS is a GREAT fit. At the ets you are running I feel they are more than adequate. I ran them on my BBF coupe and they showed me very consistent 1.51 60's. The 10.5 does fit but, does require BFH work. A 28x 10.5 on a 9" wheel w 6" BS is a good fit also, minor clearancing required.
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