# Muffler swap on stock system



## 1967pontiac400 (Dec 10, 2020)

Hey all,

I have a stock system on my 67 GTO but it's a little quiet and from what I've read through these forums, restrictive. I'd like to swap out the stock mufflers for something higher flowing while keeping the rest of the system in place for now.

I've also read through these forums that pypes is a recommended brand for our cars. Would the following muffler bolt into my existing system without needing to weld or or anything? I am not sure if the stock system is 2" or 2.5".

Pypes race pro - https://secure.amesperf.com/qilan/Detail_Web?part_num=NMVR10&order_number_e=NTEzOTcxNg== &web_access=Y

Thanks!


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## deanhickey (Apr 6, 2015)

It really depends on your budget, on the top end you could contact Gardner Exhaust Muscle Car Exhaust Systems - Gardner Muscle Car Exhaust Systems
and they could Taylor a system to meet your needs, install requires no welding and all original style hangers are included in the kit. This would be for a full system.

You will need to look at what you have now if you want muffler only option and see if it is welded together or clamped on.taking it apart can be a pain depending how old it is, due to heat cycles and corrosion. Then you have a lot of options from low to mid-range.
Another option is to just put a hole in you current muffler and see how it sounds. (LOL). high school hot rod stuff.
good luck in your choice.


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## 1967pontiac400 (Dec 10, 2020)

Thanks for the feedback. I'd LOVE to do a beautiful full system and headers, but short term I want to focus my budget on suspension and paint. 

My stock system uses clamps so a muffler swap should be pretty easy, although I think a 2.5" muffler will be too big for a stock system, right? Does anyone make stock size, higher flow mufflers?

Thanks!


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## PontiacJim (Dec 29, 2012)

1967pontiac400 said:


> Thanks for the feedback. I'd LOVE to do a beautiful full system and headers, but short term I want to focus my budget on suspension and paint.
> 
> My stock system uses clamps so a muffler swap should be pretty easy, although I think a 2.5" muffler will be too big for a stock system, right? Does anyone make stock size, higher flow mufflers?
> 
> Thanks!


You can use a 2.5" sized muffler inlet/outlet, just get a "reducer" which will fit the OD of your exhaust pipe, and ID or OD of the muffler. Most all autoparts have these and you can certainly get them on line. I would also think a muffler shop could do this if you did not want to do it. The reducers are just like any other pipe and use calmps, so not a big deal to add them. I would want the reducer which will go on the pipe side to be the one that slips over the pipe so you can adjust the muffler one way or the other. Try to get a muffler body/outlets the same as you have to make it easy. But, take a look at your local parts store first to get an idea of what it is you will be doing. If they don't have the correct size, they typically can order it. If not, online will always turn something up.


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## 1967pontiac400 (Dec 10, 2020)

Jim - thanks for the response. Do you think think would bolt right on in?



https://secure.amesperf.com/qilan/Detail_Web?part_num=N42443&order_number_e=NTE0MDg1Nw%3D%3D%0A&web_access=Y


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