The stock muffler was similar to a lot of tractor mufflers you see on old farm tractors. Rounded shape, straight through design. I'm running one of them that I got from Jim Carter truck parts in Kansas City. I like that it is not whisper quiet, but also does not have that annoying glasspack raspping sound. I love glasspacks on V8s, but our inline 6s sound terrible with them.
http://www.oldchevytrucks.com/Articles/Muffler-Tech.phpPM me if you want to hear my truck, i'll text you a clip of it.
And about the dual carb thing...does anyone actually have dyno proof that (2) 1-barrels provide any substantial power gains? My guess is it would mean more maintenance since you would have to run each one so lean.
