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My 68 Lemans has a 350 in it. I really don't want to deal with the headache's of headers. I was wondering if there is a clear favorite out there for mufflers that give the car a nice sounding rumble? The car basically has new exhaust on it from the engine all the way back, but I'm not real impressed with the sound of the exhaust. Any suggestions?
 

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I would say the ever popular Flowmasters (three chamber) or I have the Hooker Aerochamber mufflers on mine. Reasonably priced and very well constructed.

Or if you want it LOUD put on some Purple Hornies. :D
 

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Here's a different point of view...
I am not a fan of the Flowmaster sound; I prefer the sound (and flow rates) of either the Goerlich XLerator or DynoMax Welded Ultra-Flo.

They are not as brash as the Flowmaaster.
 

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A lot of the sound is dependent on the characteristics of the engine and the rest of the exhaust system.

I'm running headers, Pypes 2 1/2" exhaust, X-pipe, and Pypes Race-Pro mufflers. Here's a couple of links where you can hear what it sounds like.
(skip forward to about 1:36)

Bear
 

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I would like to know how a GTO sounds with magnaflow mufflers.. here is a short clip of mine with the Flowmasters.. (I found a test online where they checked how loud some mufflers are and for performance.. no signs that flowmasters flow worse than most others! If I find it again I will post it)

 

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The 2 1/2" system on my '67 was bent to original specs, but with an "H" pipe and the shorter body DynoMax SuperTurbo's - I also have HO manifolds. After a lot of looking, I found some data that indicated the DynoMax SuperTurbos can provide zero flow restriction up to abot 185 HP per muffler - that works out about right for my ~360 HP 400 engine. They make a great sound, although there was an obnoxious "drone" around 1600 RPM at light throttle (cruise in O/D at about 50 MPH). I had noticed the same thing on another car I put those mufflers on and that issue seems to have gone away as I put miles on the car. Or maybe I just learned not to drive at that speed/load combo :) I think the drone is getting less as I drive the GTO, too.
The headpipes are 2 1/4" in order to have enough clearance where the frame, starter & suspension monting points make for a tight fit.
 

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I have the Dynomax on my '68 Lemans with stock exhaust manifolds and used a series of pipe reducers in reverse to size the pipes up to 3" dia coming off the manifolds so I could use 3" dia. elbows and pipes (my own handy work). Mufflers end just before the rear end with turn downs. Sounds great and as TommyG67 said in his post, has a "drone" around 1600 RPM, and it sure turns heads when I am cruising down the blvd in second gear holding at this RPM. Just the kid in me I guess.
 

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I have flowmaster 44's on my ride. I think theyre kinda quiet myself. H/X pipes can really change the sound of your exhaust also.

Here's mine before I pulled the 326(sounds similar to pontiac 350) With dumped pipes before the axle at the time. Great state of Texas made me put tail pipes on the car. >:/

http://youtu.be/2yIdB_d7dn4
 

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When I replace my cheap turbo mufflers I'm gonna go with Dynomax ultra flos. They seem to be a nice compromise between sound, volume and flow. Good sound, louder than stock but not a flowmaster. Supposedly no drone, too. And affordable and available in stainless! Magnaflow has a much more "refined" sound at WOT, but is not a whole lot louder than stock.
 

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If you don't want the hassle of installing headers, Install larger exhaust pipes. (Mandrel bent) Larger pipes are always louder. I do suggest headers w/ larger pipes and a good flowing muffler set up. It's worth the effort. As most know, installing headers on a Pontiac head is not the easiest of jobs, but well worth the effort
 

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Any thoughts on the Pypes systems? I have seen a few threads on them. Anyone have experience with the different mufflers offered? Street Pro? Race Pro? Violator?
 

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Any thoughts on the Pypes systems? I have seen a few threads on them. Anyone have experience with the different mufflers offered? Street Pro? Race Pro? Violator?
No experience with a GTO, but a friend has a 2006 Mustang GT and used to have stock piping with pypes mufflers. It had a nice growl to it and was definitely not too loud. Typical "louder than stock" muffler volume but not particularly loud. Very little drone. Not sure which series it was, but they sounded great for how cheap they are.
 

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Any thoughts on the Pypes systems? I have seen a few threads on them. Anyone have experience with the different mufflers offered? Street Pro? Race Pro? Violator?
I have the Pypes 3" pro street with X over. Cannot tell you how many times I have been approached regarding the sound at idle and when stomping it. People at traffic lights will approach me. It has a distinct loud drone at 35-40mph however. The Pypes are made to bolt right up to GTOs. They fit nice. Personally, I love it, the cam lope is nicely magnified by them.
 

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to follow up on my previous post in this thread. I had Pypes 2.5 inch Race Pros no X pipe installed this spring. I have a little drone between 1800-2100 RPMs which is 40-45 mph with a TH400 and 3.55. (by calc) (no tach)
Other than that is sounds really good.
If I were to go to a gear vendor unit I would be spending a lot more time in this RPM band. 1900-2100 between 55-60mph (again assuming .78 overdrive and 3.55 rear)
still researching how to address this droning issue.
 
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