I have a Flo-Pro 4” turbo back w/ a down pipe, DPF delete, and no muffler. Also AFE Stage 2 cold air intake and EGR Delete. The truck is loud (in a good way) when you romp on it but if you just drive normal it sounds great but is still rather loud outside, but in the cab with the windows up it isn’t bad at all, just sounds good in my opinion. Or for a more mild sound a 4” with a muffler wouldn’t be as loud.

If you want it to be stupid loud, do a 5” straight pipe turbo back.

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2007.5 Dodge 3500 6.7L 4x4 SRW CrewCab Laramie
Flo Pro 4" Turbo-back Stainless Steel Exhaust w/ DPF Delete and 4" Downpipe
Smarty Programmer
AFE Stage 2 Intake
H&S EGR Delete
Pro Comp Leveling Kit
305x70x17 Nitto Terra Grapplers