I'm not running a muffler on the '96 Cummins (just the cat), using a 5" tailpipe, and it isn't all that loud at all. Some guys around here remove the cat, as well, but that's almost too loud, especially when towing.

A pair o 36" Smitty's are going on the '67 C-10 after I get it home. It'll have a sweet sound with the exhaust dumping out right in front of the rear axle and down. VROOOOOM!

Pessimist - Sees glass as half-empty. Optimist - Sees glass as half-full. Gov't- Sees glass and takes it from you because you have a glass.
Political Correctness: A philosophical belief system bereft of common sense and logic, that supports and rewards ignorance and stupidity.