I had turbo mufflers exiting out the sides in front of the tires for many years on mine. they weren't very loud compared to flo 40's, but I was still tired of listening to noisy mufflers.
When I had my exhaust re-done last year I told the man that I wanted the "biggest, quietest conventional mufflers he could fit under there, run the pipes all the way back to the bumper, and keep them out of sight"
They're 2.5 in/out. They flow fine, and are really, really quiet. These along with decent sound insulation in the cab make for a nice quiet ride. I have long tube headers, and a mild cam that add a subtle flavor to the tone. I'm quite pleased with the way it worked out. I got exactly what I wanted for a total cost of $250. It's not stainless steel, but here in NV my last exhaust system lasted 12 years. At that rate I'll be 65 the next time I replace it.
