I have the same exact muffler 18 inches in length with OBX LTs, the resonators that came with them and true 2.5 inch duals all the way back. Mine sounds awesome under idle with my 224/230 cam and nasty as hell under WOT.

 

How's the interior noise level?

 

Well i had a few exhaust systems before this to compare it to and its actually about medium. Its got a drone but its not as bad to make anything vibrate like a dumped 40 does.

 

This wasnt on my chevy but, I had JBA shorties, high flow cats and a 14568 Magnaflow all 2.5"ss, I think its the largest muffler they make. Exiting in front of the right rear tire. It had a nice deep tone at idle and really woke up when you stomp on it. Zero drone to.
I'm getting the same muffler for my new set up.

 

I had that muffler on my 6.0 for a few years and Loved it!

 

what are you looking for? quiet? no drone?

 

can u put an x pipe where it should go ? , and then that magnaflow muffler, or would it be a prob cuz it has an x built in ?