Pontiaker

My drivers side stock muffler started rattling, buzzing, vibrating when the car was fully warmed up. Nothing wrong on the outside and everything was tight. Found and bought a brand new pair of Z06 mufflers locally for $200, replaced the drivers side muffler and the noise is now gone.

I cut open the muffler that same way you would if you were going to do the muffler mod for better sound and found one of the internal end plates had two large cracks in it.

I am going to mod two of the mufflers for the better sound and will also have the internal end plate cracks welded up. I am thinking of useing one muffler on my Trailblazer SS in place of the stock muffler, rig up a vacuum line with a valve to control the Z muffler. The TB SS muffler is close to the same size and will look mostly stock.

Or, I might install both mufflers on my 1970 GTO. This was actually a super rare option on all 70 GTO's but only about 200 cars ever came with it from the factory before the option was pulled by Pontiac, cant remember why though. My dad bought all the stuff except for the mufflers, to add this option to his 70 GTO so I have all the parts to do it. The only problem is the Z mufflers are thicker than the stock mufflers but there is so much room under there I think they will still fit.
Matt

KLLRVET

One of mine did it, and it was fixed when the muffler mod was performed.

capevettes

My stock mufflers are sitting upstairs in my barn. They would make nice boat anchors. The only problem I had with them was they were too quiet.

Pontiaker

Are they the dual mode Z mufflers? When mine are open they are very loud, but I also have a cam and long tube headers, cross over pipe and high flow cats...I get more compliments about the sound of this Vette than any of the last 54 cars I have owned! Lol! I really love the option of closing them on the freeway, long trips or when the wife is in the car! Lol...

capevettes

Yes, they were the stock NPP dual mode Z06 exhaust that I took off. The rest of my system is stock except for the Bullets. With your setup anything is going to be loud. Drone never bothers me, even on the highway. Of course I've been listening to factory side exhaust in my 65 for 40 years, so loud is good

0Louis @ LG Motorsports

its quite common above 20-30k miles, some track cars see failures in the 10k mile area.

Undy

My passenger side did. I simply replaced it with a used muffler from a board member.