Off road exhaust?

[Keith G.]

So what does off road exhaust look like for 1967?

[William C.]

Re: Off road exhaust?

From the trans crossmember back, same as 65-66, the front pipe is '66 style, with the two inch manifiold outlets meeting a 2 inch pipe swedged into the 2 1/2 inch pipe back to the trans tunnel crossmember.

[Tom H.]

Re: Off road exhaust?

From the trans crossmember back, same as 65-66, the front pipe is '66 style, with the two inch manifiold outlets meeting a 2 inch pipe swedged into the 2 1/2 inch pipe back to the trans tunnel crossmember.

I hate to sound stupid, but does anyone have a photo of a "swedged" pipe ?

[Thomas G.]

Re: Off road exhaust?

Here you go. The front pipes started out as a 2" pipe and then were welded in to a 2 1/2" section for the rest of the pipe.

Hope this helps.

Best Regards,


Eric Gardner

[Bill I.]

Re: Off road exhaust?

It was a joke. The word is swagged. Bill.

[Tom D.]

Re: Off road exhaust?

I am guessing you are aware that both Allens and Corvette Central (CC) are sellers and the systems are internally diff. Newest repros of N11 "off road" mufflers come from Waldon (or Waldron?) in Detroit area and get sold by CC.

Do a search for "stink ray" on the internet to find a video on you tube that gives the sound of one of these systems. The car is a high cube 67 big block in yellow.

Most people agree that the CC version is louder. You may consider that better or not better, depending on your taste in "exhaust notes".

[Tom D.]

Re: Off road exhaust?

I found the video by using other words (including N11). It's under the title

"Corvette C2 off-road exhaust 1967 Coupe" and I am sure this was not the Allens version.

http://video.google.com/videosearch?q=you%20tube%20stink%20ray&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wv#q=N11+exhaust&hl=en&emb=0&client=firefox-a

[Terry M.]

Re: Off road exhaust?

Here you go. The front pipes started out as a 2" pipe and then were welded in to a 2 1/2" section for the rest of the pipe.

Hope this helps.

Best Regards,


Eric Gardner

Swagging (or however it is spelled) involves reducing or expanding the pipe size by mechanical force. If reducing the diameter a machine that hammers on the outside of the pipe reduces the diameter. This is the process used on the original exhaust pipes. If expanding the pipe a die that is slightly larger in diameter than the pipe is driven into the pipe. Successively larger dies can increase the diameter of the pipe. This process is most often used on copper pipe to expand one pipe so the next pipe can be soldered inside the first. It is often used in the refrigeration industry.

There is a process of swage welding that joins two pipes together, or joins a pipe to a corner fitting. I have seen this proprietary process used to join aluminum pipe to cast aluminum fittings in electric utility substations. I'm not sure that this has any application in the automotive industry.

[Gary J.]

Re: Off road exhaust?

www.gardnerexhaust.com is another suppler too of the N11 system.