2004 5.3 Muffler / Exhaust Pipe Diameter

[huminski]

Hi,

Does anyone know for certain what the inlet and outlet sizes are on the factory muffler. I measured the pipe at the exit (across the opening) and it is 2.75"OD. I don't have a caliper so it's hard to measure it anywhere but across the end opening. My local shop has Flowmaster 40 and 50 series but only in 2.50" or 3.00". Does the factory pipe flare out from 2.5 to 2.75 at the tip or is the entire system 2.75? I just want to cut out the factory muffler and replace with a flowmaster, retaining the rest of the factory stainless system.

Thanks!!!

[jeverett]

The exhaust shop should not have any problem fitting a flowmaster in the stock location, IF they know what theyre doing. THe shop where I used to work at, if the pipe was 2.75, then I would use a 2.5" muffler and slip it inside the stock pipe.

[huminski]

Thanks. That would create a little extra restriction I would think, but it would work. Regardless, I bit the bullet and ordered the Gibson super truck system. I had the ExtremDuals on order, but I saw a few pics of them actually installed and it wasn't the look I thought it would be. In my opinion you could see way too much of the pipes. My dad had the super truck system on his 1998 Ram 1500 and it sounded really good, it's loud which is what I'm looking for and it looks different. If it was legal I would just run a straight pipe but I need to pass inspection, ya know?

Thanks again!

[BigRed04Silverado]

I just recently had the 40 series with 2.5 pipes put on my 04 5.3. It sounds great, almost a little to loud and performance seems a bit better but nothing drastic.