if you dont mind failing emissions tests or raspyness, then test pipes, if you want a nice change in the exhaust note and pass emissions, HFC's.
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2011 Mustang 5.0 | 3.55's | Lethal Performance off road H-Pipe | Magnaflow Muffler Delete | JLT CAI/Bama tuned 417whp/ 404 ft/lbs
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