6.6L L8T Gas Exhaust Options - MBRP, Borla...

powderMonkey · January 24, 2022

Time warp! I finally spotted the MBRP T304 in stock at Summit Racing, and drove up and got it from their Cleveland store, and also the matte black tip. I just installed it on the 4-post lift at the shop yesterday. I only drove the 5 miles home last night because I was exhausted (no pun intended) but it does sound good! Not too loud in the cab but you know it's there. I am headed back to the shop now to do a couple other things (we are closed today), and I'm going to get some pics and videos, and will reply back to this soon with some info and what I learned from the install.

sheath · January 24, 2022

4 hours ago, powderMonkey said:

Time warp! I finally spotted the MBRP T304 in stock at Summit Racing, and drove up and got it from their Cleveland store, and also the matte black tip. I just installed it on the 4-post lift at the shop yesterday. I only drove the 5 miles home last night because I was exhausted (no pun intended) but it does sound good! Not too loud in the cab but you know it's there. I am headed back to the shop now to do a couple other things (we are closed today), and I'm going to get some pics and videos, and will reply back to this soon with some info and what I learned from the install.

looking forward to this! :thumbs:

sheath · January 24, 2022

double post... Sorry!

Edited January 29, 2022 by sheath

sweatandsteel · January 29, 2022

For those interested, I just got an email from Magnaflow that their street series cat-back exhaust system is available again for the 6.6 gas engine. I need to go make some money....

Builtrockhard · February 23, 2022

On 1/24/2022 at 8:13 AM, powderMonkey said:

Time warp! I finally spotted the MBRP T304 in stock at Summit Racing, and drove up and got it from their Cleveland store, and also the matte black tip. I just installed it on the 4-post lift at the shop yesterday. I only drove the 5 miles home last night because I was exhausted (no pun intended) but it does sound good! Not too loud in the cab but you know it's there. I am headed back to the shop now to do a couple other things (we are closed today), and I'm going to get some pics and videos, and will reply back to this soon with some info and what I learned from the install.

So what’s the latest? I’m looking to get this system for my 2022 AT4 HD

sweatandsteel · April 12, 2022

Well after doing lots of research I discovered the Flowmaster Outlaw stainless dual exhaust system for the 6.6 gas and took the plunge. It was delivered on Friday and hope to get it installed over the next couple of weeks and will update everyone on how it goes.

Mic_ · April 12, 2022

On 3/9/2021 at 9:57 AM, powderMonkey said:

I was wanting the MBRP T304 system, so I called MBRP yesterday and got a recorded message that they are not taking calls, and to contact them via the website. I did that and got an instant response, but it was not at all what I wanted to hear:

ME: I am wanting to purchase T304 exhaust part number S5093304 for my 2021 2500HD. Are those in stock and available to ship? If not what is the lead time roughly? And would it be possible to swap out the chrome 4" ID 5" OD tip, for your black dual wall 4" ID 5" OD tip part T5053BLK? Thank you!

MBRP: Sorry, they are out of stock and it could be 6+ weeks at this point. Sorry, you cant swap tips.

Borla's own website says "coming soon" for our trucks, yet it is listed as an accessory on the official Chevy Accessory site. What is the deal with that? Has anyone successfully gotten a Borla direct from Chevy? If so what was the lead time on that?

Official Chevy Accessories Borla Cat-Back Link

Any info fellas? Or other options? Thanks!

looks like amazon

bought all there stock up??

https://www.amazon.com/MBRP-S5259304-T304-Single-Back/dp/B00XC1JSFC?th=1

CT Chevy Connoisseur · April 13, 2022

On 4/12/2022 at 7:31 AM, sweatandsteel said:

Well after doing lots of research I discovered the Flowmaster Outlaw stainless dual exhaust system for the 6.6 gas and took the plunge. It was delivered on Friday and hope to get it installed over the next couple of weeks and will update everyone on how it goes.

good luck, personally I didn't even consider anything that wasn't 304 stainless as I don't plan on ever replacing it

Randal Scott · January 17, 2023

AFE makes a cat-back kit made of 409 stainless steel. For around $600.00. I found a muffler from Walker 21470 with 3.5 inch inlet and outlet. Probably have to add a short piece of pipe to the tailpipe.