4.8 Exhaust

ibag8rfan · April 12, 2009

Would you guys recommend going with a 3" single in/out exhaust, or should I stick with the stock size (2.75" i believe) and just put in an aftermarket muffler? Duals are out of the question as pretty much 90% of trucks around here have it and I personally don't care for the look. I don't want it to be extremely loud, barely louder than stock actually would be ideal, but I would like to gain at least 5 or 10 hp with it too after adding a tune.

I'll most likely have it turned down right past the muffler and have no exhaust showing. How does that affect sound in the cab? This is my first truck (actually my first domestic vehicle or 8 cylinder for that matter).

MikeInCtown · April 13, 2009

3" exhaust will be fine but the turndown you suggest is going to make it loud as hell and really annoying inside the cab.

I just installed a Summit dual system in my truck this weekend. I drove it around for a while without the tips on it and it was very loud at all RPMs and I didn't like it one bit. Adding the 12" tips to extend the system to the bumper made it a whole lot quieter inside. Still loud at some RPMs but much better than it was. What's worse is that I get the resonance at almost the xact RPM range I do mst of my driving in. Will probably change the system again at some point this year.

October 29, 2009

i just did the exhaust on my 4.8 i have jba headers no cats cherrybomb extreme si/do soon to have 3&1/2 in side tips my you can hear me blocks away when i get on it

BigBlueLB756 · November 4, 2009

I see where Gibson has duals made with the Superflow CTF muffler that "supposedly" handles the dreaded AFM/DOD drone that occurs between 68 to 74 mph (highway cruise). If they work, and I don't know for sure that they do, I would seriously consider trying a set. Anybody using them?