The stock overall diameter for your stock exhaust from your exhaust manifold to the tailpipes is 2.25". But most will upgrade to a 2.5" for more flow and less restriction. You can stay at 2.25" from your exhaust manifold to the muffler, then go 2.5" from the inlet of muffler to the tailpipes. But if you are only changing out the mufflers and nothing else, then stick with stock diameter. If you go 2.5" for the muffler only, but all your piping is 2.25", you have accomplished nothing.
2015 Race Red Performance Package GT 5.0 (435hp) stock
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