I dumped my exhaust yesterday.

 

Badram...that is a really small muffler. Your truck must be loud as hell!

 

I have that same muffler. Its a one chamber flowmaster. Mine was also dumped until yesterday.

I ran open with no muffler to the exhaust shop, and it was just as loud with the one chamber as the open exhaust was. The only thing that changed was the tone.

Heres a vid dumped:
http://www.youtube.com/watch?v=sm8IuF0yfak

Heres one with the exhaust ran out the back, same muffler. Its louder outside like this, but quieter inside.
http://www.youtube.com/watch?v=CQ6PvlckcDY