Truck: 2011 Silverado CCSB z71 4x4 5.3L Exhaust will be turned down..

Question 1: So as the thread states I'm looking for the pro's cons to the oval vs round magnaflows.
Question 2: I'm also curious what do the different muffler diameters offer on the round ones. I know length is proportional to sound with longer being quieter, but I see there are 4" diamter and 5" diameter etc.
Question 3: I formerly had a 40 series on a 5.3L, and went with a 50 series on a 6.0L. I have since realized how bad chambered mufflers are from a performance perspective and was wondering which magnaflow muffler size likely compares sound wise the most? I was thinking 18" muffler body. Thoughts?

 

A 18" oval case should sound similar, in my expirience the round cases are fairly loud.

 

Here ya go man, answered your questions in red.

 

More volume = quieter

 

Bigger the muffler the quieter it will be the smaller the muffler the louder it will be. I have a 24" oval and it is basically stock sounding at idle and purrs like a lion at wot. Brother in law has dual 5x14" rounds and its loud as hell.

 

exactly. volume can be had with either length or width or both. muffler internal design also plays a factor. but pretty much rule of thumb is if you want loud go with small mufflers; if you want quiet, go with big muffler.