I have two pipes going all the way to the muffler where it changes to a single pipe. Most pictures I see of after market systems for these trucks have a single in single out or single in dual out.

 

IS this a 6.0l? IF so then you do have different system from 5.3 an 4.8 which you see in most pictures.

 

their is a muffler that magnaflow makes that is dual in and out and has a built in x pipe into the muffler. or since your already half their install true duals. and run a x pipe. What kind of sound do you want to get out of it and what kind of truck do you have?

 

You have the Texas Edition excab LQ9, right?

If so, your stock muffler has dual 2.75" pipes going in, and basically a single 3" going out. If you get a replacement muffler, get one with a dual 3" inlet.

 

That is correct.
I am trying to find how this truck is different. So is my exhaust the same as the LQ4 equiped trucks as well? Or is it just an LQ9 thing?

Thanks

 

I just looked at it again and it is a dual in dual out. The dual out quickly Y's into a single pipe. It really seems like a good system for being stock.

 

Well, I don't know if you are looking to change anything but I have an SS muffler on my 5.3 Z71. It complemented my Nelson Tune very well. It looks like yours and may be the same. Corsa says it flows around 160 CFM more than my OE single in and out Z71 muffler. I hear FloPros are quiet but flow better than the OE SS or perhaps what you have. Call and speak with them.
http://www.flopro.com/FloPro.htm
You can try and call Corsa too about the flow rate of the muffler you have. An engineer there is who told me they flow tested many of GM's mufflers. They make the OE corvett exhaust.

 

I am not wondering about changing it right now. I am just trying to find out what kind of "Special Options" my Texas Edition excab LQ9 truck. There is not a whole lot of info about this truck out there so I am trying to piece it together.

When I do change it I think I will just add two 20 or 40 series Flowes and a X-over pipe to my current piping. Dual 2.75's is not bad at all and will make it very cheap to upgrade.

 

I had the same on my 6.0 LQ4. I think the stock exhaust is pretty restrictive, but not the end of the world. I changed mine b/c I wanted to actually hear my engine. Performance wise I don't think there is a huge gain unless you start adding some other good performance mods.

 

If you look at the front pipes, they are the same crimped 2.5" pipes and cats that come on the 4.8/5.3 trucks. Then they merge into the 2.75" pipes. It sounds like your muffler is the same one that I had on my SS. Its deceiving, it looks like a dual out muffler, but one of the two outlets is blocked off inside the muffler and has no flow. That basically makes it a single out.