I put in a 3 inch Stainless works catback exhaust and it fits just fine under the stock tunnel brace. Just make sure that all the pipes are in a straight line and not twisted! If it rattles, it's not on right! TRUST ME.
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'14 Camaro 2SS/RS
Performance Mods:
Roto-Fab CAI || Stainless Works CA11CB Catback 3" Exhaust || Speed Engineering Long Tube Headers || Elite Engineering Catch Can || GM OEM Strut Tower Brace || SCT Tune from Steve @ RDP
Aesthetic Mods:
Exterior: "SS" Badge on each side || Black Front Bowtie || Z28 Replica Spoiler || Tinted Tail & Headlights || Painted Matte Black Wheels ||
Interior:Black Painted Top Dash Bar || Black Painted Shifter Bezel || Black Painted Shifter Base || Custom Cock-Back Shifter with Shift Buttons || Black Painted Door Insert Panels || Black "SS" Door Kick Panels