How loud is it in the cabin? I want a little noise not obnoxious.

 

If you want a bit more reserved sound but still want to turn heads when you put your foot in it, go with a Magnaflow. Nice deep note without the "hollow can" obnoxious drone. A good muffler shop should be able to describe the different sounds to expect from different mufflers.

 

I have the 50 series on my 02 4.7. When the pipes are cold you get alot of noise in the cab. Once it is warmed up only at certain RPMS. On the highway 65-70 you get some noise, but it you rap the throttle it will go away.

 

They're loud for sure.

 

is there any way to tell what series Flowmasters you have after they're on the truck?

I know one of the service writers at my local dealership and he installed mine for cheap when I bought the truck, so I have no paperwork on 'em

they're loud as hell though