Hey I have a 04 Denali and my factory muffler has rotted through finally and its time to replace it... Problem is I can't seem to find the exhaust diameter size online that may be right. Ive seen 2.5, 2.75, and 3.0 inches. I haven't been under the truck yet to measure it myself and can't find a thread here with an answer. Also I'm looking for muffler recommendations. I want something that flows better and has a deeper more aggressive tone. Also wondering is it possible to run two exhaust pipes next to each other with two mufflers instead of one from original muffler position that could exit together on the same side? I will eventually be doing heads, cam, headers etc. Any help would be appreciated. Thanks in advance.