my dad got a 01 2500HD 6.0 4x4 pickup for the farm... well the stock muffler had to go, so he got the idea to put true duals on the truck. Anywayyyy, he went to get it done and I figured he would get mufflers. Later that day I heard this loud "jet boat" sound coming about 5 miles away. Sure enough he had true duals with NO MUFFLERS... OMG, talk about loud. About 4 times louder than my TA with the cutout open

anyway, he had to go back and get muffler sput on. Some V force ones but man does she sound nice and mellow now(still very loud). Awesome cammin sound too

I gotta get one of my own cause I love this truck to death... low end and mid range is totally unreal

im just glad I get to drive it everyday at work

for you guys with no mufflers on these trucks, i dont know how you stand it. I have no muffler on my ol 94 4x4 and its no where near as loud as the 6liter!!! My 98Z71 has dynomax bullet mufflers/true duals and you cant even hear it next to his truck

 

Hey man did he take the cats off? I have duals with no muffler but left both cats on and it isn't too loud. I am about to take the cats off and put two bullet mufflers with xpipe to hopefully make a little more power.

 

I have true duals with the cats still on, Hooker Aerochamber mufflers and axle dumps, I still have great low-end and the sound is KILLER.....nice and mellow at idle with a GREAT growl when you hit the throttle, it does have just a little bit of an in-cab resonance at 45mph or so but at hwy speeds you can hold a conversation with no problem.
I am going to MagnaFlow mufflers, an "X" pipe, and angles tips when I have the tuning and cam done in Oct-Nov so I will see how much of a change there will be then

 

yes the cats are still on.. with straight pipes the exhaust would resonate its AZZ off above 3000rpms. But like I said... a 5.3 or 5.7 wont be as loud as the 6.0L's. I love no mufflers on the 5.7 liters
I swear the truck still sounds like a jet boat cruising down the water. The heavy duty transmission sounds like she has a 4k stall in her also which makes it a little louder

 

I made my own duel setup with two bullets going into a H pipe and then into duel edelbrock RPM's. I put duel 2.5 out the back bumper. It sounds awsome at WOT and low and mean just driving with no resonance at cruise.

 

I had true dual. I had 30" Thrush packs first. Sounded real low and mean at cruise. But hit the loud pedal and my god it talked to ya. Then I had 40 series Flows. The resonated to bad. Now I have a dual in/out Flowmaster 50. I like how it sounds, the low end is great. Probably will stay with this set up for a while.