Hi, I'm new here so forgive me if this question was asked and answered here already. I'm taking delivery of my new '08 Crew Cab AWD Sierra Denali shortly and I have been trying to find a cat-back exhaust for it, but no one seems to make one.
I've been told that the pipe on the Denali is bigger than the usual 3" because of the 6.2L. I 've also noticed that the Magnaflow exhaust for the Yukon Denali w/ the 6.2 is 3.5". I think the 6.2 probably needs a 3.5", especially with a few mods.
Does anybody make an exhaust with the large pipe for this truck?

 

Corsa makes a VERY good one I believe. Sounds great and no drone.

 

You should able to find a direct fit Corsa or Magnflow cat back for around 500, in stainless.
muffler shop could also do a custom muffler only for you as well

 

Cheapest I found corsa for our 2008 sierra Denali was $800. I decided to go the route of putting in my own muffler. Going to try the Aero 3535xl as I have heard there is no drone with it with its bulit in resonator and keeping the stock resonator over the rear wheel. Hopefully the people that said that are right. It is a 3.5 in out so same size pipe as stock but straight through design.

 

Thanks very much guys. I have seen that Corsa makes a kit for the Sierra Denali, but I couldn't figure out from their website whether it was a 3.5" pipe. I measured my exhaust tip and the stock pipe looks to be slightly less than 3.5" i.d. (more like 3 7/16" o.d.), so a true 3.5" i.d. pipe would no doubt flow better especially with mandrel bends. I think a 3.5"i.d. muffler will slide right over the stock pipe, because yesterday I tested the fit of a Magnaflow 3.5" tip over the tailpipe and it fits snugly. The stock exhaust has a muffler and a resonator and you can still hear that its not a 5.3, so I'm sure that a just a single direct flow-through muffler will be quite loud ( I like loud, but only at WOT!). I have heard good things about the Hooker Aero muffler though -they've basically perfected the concept that Flowmaster came up with in the early nineties - sound waves cancelling each other whilst at the same producing nearly as good flow as a straight pipe. I like the sound of a Flowmaster but I think the Aero is a superior design.
I think I'll go with the Corsa, if I can confirm that it is in fact a 3.5".

 

Mine is not the hooker aero, its the aero turbine. Looks like this:


Im pretty sure the Corsa is 3.0". I saw elsewhere that they chose to choose this pipe size as it gained better results than their system with the 3.5". The muffler I am choosing was originally designed for a diesel engine to increase the noise slightly but not make it too loud while giving it the flow. Our stock mufflers are actually not that bad when it comes to flow. Pretty much makes two u turns to go back out. I do not want my exhaust too loud either just a touch over stock. I also refuse to have drone haha. I guess I am going to have to wait to have time to install to see if my hopes are fulfilled haha

 

Nice Looking Muffler. Never heard of it before but looks good. Let me know how it goes.

 

YEA maybe go with borla or corsa,another thing i still havent found a cold air intake for my 09'denali.i ordered a gmpp intake but didnt work cause of the maf sensor.

 

I would like to know how pleased with the Aero mufflers you are. I have been reading about them and am impressed with what they have to offer, atleast the literature is impressive.

 

So there's a difference between the 08 and 09 MAF Sensor?