Trying to pick out a catback for my new 2015 6.2. The truck will be getting a tvs1900 so I need to make sure the exhaust is sized for that. I want to stick with a catback with 304ss. That kinda limits me to borla or Corsa. Corsa is a 3.5" single and borla is 3.5" in, dual 2.25 out. Dual 2.25 seams kinda small to me for the power output of sc 6.2. I would think it would help with low end torque, but I bet it would choke it bad up top. Thoughts?

 

3.5in is fine a single. 4in seems overkill.

And 2.25 for true duals is plenty aswell, it's only passing exhaust from 4 cylinders and you'd never overflow that size. Unless maybe you made a crap ton of power.

 

Get the 3.5" Corsa

 

No Headers then? Headers size might have more to do with scavenging exhaust gases to help with torque but only at very low rpm's, something you really don't need to worry about as the SC will make a ton of torque, 3.5" single be more than enough and would lean in that direction personally. Consider long tubes headers for your build if you haven't yet.
ps I am no expert so take my advise with a grain of salt as they say....

 

Maybe it's a sign of age, but my current exhaust combo on my 03 is longtubes w/ cats and corsa and it's just too loud for me. I've actually caught myself not being aggressive with throttle due to noise.

 

With the factory manifolds etc the cat back won't be your biggest restriction. Go with a 3.5 for sure.

I'd also think a corsa is the way to go. Maybe the touring?

 

I would have thought the truck had a 3.5'' cat back factory??

 

I should also add another monkey wrench is I really want the hellwig rear sway bar to fit. I haven't really found many threads saying which do and do not fit, but I was able to crawl under a truck at the dealership that had the borla dual exhaust and based off where the hellwig rear sway bar mounts, I believe it will fit. I haven't been able to see how the corsa exhaust runs on either a gmt 900 or k2xx to see if there is room.

 

I tried getting a touring for the new body style. I emailed corsa and they said the touring has come up in the past but as of yet they are not going to release a cat-back in the touring model

 

Leave the stock exhaust on and put headers instead. You'll get better performance. Stock exhaust flows fine.

My truck has kooks, no cats, stock 3.5" exhaust.