Stacks. or Just Stack.
pros.
Looks awesome if you like that kind of thing.
sounds really good (Especially the turbo echo)
cons.
Dumps right behind the cab, so its rather loud.
must cut yer bed and give up space in it for installation.
cant really smoke anyone properly since its straight up.
If you tow Horses at all with a bumper pull they get a snootfull every time you accelerate.
Rain is a concern if you dont put a flappercap on or 90o it.
MBRP 4"
Pros.
Sounds kick ***, with or without the muffler.
Dumps waaayy behind the truck so even without a muffler its not obtrusively noisy, and retains the nice turbo echo.
puts a nice sooty cloud right in the face of whatever idiot happens to be tailgating you irritatingly close.
Horses in bumper pulls dont suffer a snootfull of acceleration.
Rain is not a concern.
No cutting of anything or giving up bedspace to install.
Cons.
