LNCHBOX

14" will be too small if you don't want drone. 18" is the smallest I would go.

mpossjr

I just got this same set up but single out. I have a 2013 5.0. I kept the stock pipes and resonator. Added 2.5" in(center), 3" out(offset). Sounds great! Can't hear it on the interstate. Just enough rumble without it being too loud inside the cab. There is a slight drone at around 40 mph 1,500 rpm. I'm happy with it so far. You could prob. go with a 16" or 18" and it might get rid of the 40 mph drone. I tested out the phone quality through sync and no problems on either end.

Greeny

Installed Flowmaster 40, 3 inch, single in, single out, kept resonator and stock tail pipe. Nice rumble on start up, when warm you almost can't hear it idle at all. Sweet rumble while accelerating, but not obnoxious. You can just hear the rumble at highway speed if the radio is off. There's no drone at all.

brc1989

I was all about flowmaster until I realized they are chambered mufflers and the factory muffler is straight through on the 5.0 trucks so I don't want to go backwards, so im leaning towards magnaflow now although I still kind of like the flowmaster sound.

zimmer0

iTrader: (1)

In front of tire would have slightly more drone as the exit is closer to the cab.