GMC 1500 6.0l muffler - Anyone know what size the exhaust pipe is on a 2009 GMC 1500 6.0l, and which magnaflow muffler would fit. Looking for something just a ...

Anyone know what size the exhaust pipe is on a 2009 GMC 1500 6.0l, and which magnaflow muffler would fit. Looking for something just a little louder than stock.

Most likely it is 3.0" or 2.5". Any Magnaflow would fit, as long as it fits the stock piping diameter.

^^^ +1 on the size.

The 5.3 is just over 2 3/4", close to 3". If the 6.0 is dual to the muffler it might be 2.5". I would measure it or take it to a muffler shop that has stock to fit what ever your exhaust pipe is. I had dual 50 series Flowmasters on my 03 SS and it was loud on cold start but sounded great all the time even though it had a little drone at highway speeds. I have swapped to Magnaflow now and that is what I have installed and will install from now on. But muffler brands really are a personal preference, just go bigger if you ant quite.

I know my 04 2500hd 6.0 was true dual 3 inch to the muffler.

I measured at the end of the exhaust pipe. It was about 2 3/4". It looks to be the same size at the muffler. Would 3" muffler work?

Blane wrote:I measured at the end of the exhaust pipe. It was about 2 3/4". It looks to be the same size at the muffler. Would 3" muffler work?

If you are having it welded yes it will work. Stock is 2 3/4" inside diameter but the piping is pretty thick puching the OD to around 2 5/8". Measure the outside diameter of your stock pipe and see how close it is to the 3" mark.