I know that this topic has been beat to death already, but I have a quick question. I am looking for new side pipes for my 67 427/400 and I am trying to find a set with as close to factory sound as possible. In reading the old posts about this, I found a lot of suggestions. The problem is that many of these companies are no longer in business. Can anyone steer me toward the best option that is currently available?

Thanks, Doc

 

Doc - When I bought my 65 396 Roadster (NOM) back about '3' years ago, I found it was an original side pipe car but it had what looked to be a brand new set of aftermarket side pipes on it.
When the seller started it up and we drove down the street, the first thing that crossed my mind was...'The neighbors are going to start throwing things'. The 454 in there was warmed over but
it was the side pipes that sounded god-awful. I have three other midyears, one Bigblock and two Smallblocks with GM side pipes and they all sound just right.
The set of pipes on the 65 turned out to be, as best I could figure, made by Sweet Thunder which I believe is now called Top Flight or something like that.
The interior baffles on the ST pipes are huge compared to the much smaller perforations on factory pipes.
I sold off those Sweet Thunder pipes to another Forum Member and surprisingly, he's still talking to me :-O.
I checked around and found not a lot of aftermarket side pipes availabe but one outfit back in New York, Gardner Exhaust, is one that comes very close to the original factory sound.
Back a year ago, I was on their site and they have some videos of customers cars with their products and they sounded good but I contacted Gardner and asked if they might put me in touch with a couple
of those customers. They did one-better, they gave me the customers email addresses which led to phone calls and both customers were still happy with their Gardner side pipes after having them on there for some time.
Just yesterday, I called up Eric at Gardner and placed an order for a set of new Bigblock Side Pipes. The bad news is it's going to be over '4' months before I see them. That's okay since I'm still working on the 65's new Bigblock engine
and have the heater core out as well.
Mike T - Prescott AZ

 

Mike,
You are "The Man"? How is the "Project Creep" with the Core Project? It might be past 4 months for me on replacement side pipes....Let me know how they sound relative to the one's removed........

All the best,

Doug

 

Hey Doug - That's the perfect name for this 65 NOM L78 Roadster, Project Creep. I contacted one of the previous owners, Larry Johnson, who owned the Roadster back in 2010-2015 and asked if he recalled ever replacing the heater core.
I've gone over the car from front to back and didn't even think about the heater core until I found the core in the 66 BB Roadster leaking profusely. He couldn't remember ever having to mess with the heater on the 65 soooo, I pulled it out and found
someone had already been in there before me, as the core had the same sticker on it as the new one I replaced in the 66 stating it was Made in Mexico. No matter, it still sat around for a lot of years so one less thing to worry about.
Back to the side pipes from Gardner, I checked in with them back in February to get a price quote but got wrapped up with the 66 so just never placed the order until yesterday. I had had talked with two of their customers, a Ken McKinley from Rhode Island and another customer, who I thought lived out in SoCal and both liked what the Gardner Side Pipes. If you go to the Gardner website and click on Sound Bites, scroll down to 67 L71 with Side Pipes and you'll hear them.
I'm getting Old(er) and can't recall if you did already buy new side pipes? And did that vibration problem finally get solved?
Mike T - Prescott AZ

 

Thanks folks, I did listen to the Gardner clip and I spoke with them on the phone. They are proud of their pipes, but that is OK if the really do work as advertised. Doc

 

In addition to gardeners, I would check these guys out, I understand they are producing the original configuration internals, that produce the “original sound”?, although I’ve not heard them myself. These are not the large louver internals that they use on their larger core side pipes.

 

The build quality and fit of my HiFlo's are excellent. I bought 2.5" Inner x 3" Outer stainless. I'm sure they don't sound original. I've commented before about the bad rap of stainless exhausts sounding tinny. That rep, I'm convinced, is from stainless mufflers made from much thinner sheet metal than standard aluminized mufflers. I'd definitely use HiFlo again. They now sell quiet versions FYI.

 

I just looked again at the HiFlo website since I was hoping to get my 65 L78 back on the road before Christmas since Gardners is talking about an 18 week lead time. I did run across what HiFlo advertise as Aluminized Original Sound and they show them for Smallblocks and Bigblocks, but their cost is actually a little bit higher than Gardners. I will contact them and ask for a pic of their interior baffle setup. I've had '5' midyears with side exhaust and '4' of them had GM pipes and sounded great, with the one lone exception being the large baffle Sweet Thunder Pipes which sounded louder and more along the lines of obnoxious. Has anyone bought these Original Sound Pipes from HiFlo in the last couple years? Love to hear what you have to say about their Original Sound pipes.
Mike T - Prescott AZ

 

I just ordered a set of HighFlo side pipes from HighFlo Performance. I had just ordered the big block Head Pipes from them and installed them on my existing muffler side pipe. Do not
like the sound. I hate to say it, but a little too loud. When I talked to the owner of HighFlo, who was very nice to talk to, he recommended the MY 4001 side pipe. They will weld right to my head pipes I just bought from them. They are supposed to be very similar
to original sound. By doing this it was half the price of the complete side pipe from exhaust manifold to tip. I hope to get them in a week or so. I will let you know how they sound.

 

Don - I know we've had a lot of input on other SE threads but just can't recall...which brand of side pipes were on your midyear that you just added the new head pipes to?
I ordered my 'original sound' pipes from Gardners back on 9-7 when they mentioned 18 week delivery estimate. Called again on 10-14 and now down to 4.5 - 5 weeks. I thought I'd be
'ready' for the pipes then but...uh, not really, the new 427 isn't even in the car yet, maybe a week away :-(.
Mike T - Prescott AZ

 

Mike,
The side pipes that I added the new head pipes to were on my car when I bought it 20yrs. ago. They were GM small block pipes, but pretty burned out.
I finally got my 468 in my car and running. It was lots of work, but I am very pleased with it. Just need to quiet it down a little. Trying to make the wife happy.
Don

 

Don - I'm envious, looking at your engine compartment. My 65 L78 engine compartment has been vacant for a couple years and I hope to change that soon.
Back to the pipes, I found that the 'new' aftermarket side pipes that were on my L78 were made by Sweet Thunder which is no longer around. They really looked like
they were just taken out of the wrapper but a pic of the interior baffling showed large baffles, not the smaller versions found in GM pipes. So, I do like GM pipes
or aftermarket pipes that have those same small baffles but having owned another factory-side-pipe car a number of years ago, I agree that they can and do wear out making the sound not so pleasant.
Maybe that's the wrong phrase to use...'wear out' but my best guess is that those sets of stock GM pipes had corroded enough internally that some of the baffles had broken loose and they
just sounded off. I know they make quite a few different versions, I looked up their MY 4001 pipes but no pics of the internal baffling. Do those Original Sound pipes have the same 'small baffles' as the GM pipes?
Same question for the OP...Doc, do you have any particular pipes you're leaning towards?
Mike T - Prescott AZ

 

Mike,
The HighFlo MY 4001 side pipes have the 2" baffle. The original sound GM pipes had the 1 3/4" baffles. HighFlo also makes a 1 3/4" baffled side pipe. I think it is MY 5206-C. With my 468 I wanted a little more flow
than the original size 1 3/4" baffle hoping the sound is not much more than the original sounding GM side pipes.
You should call HighFlo and talk to them.
Don

 

This is who I bought my side pipes from for my 66 and they are a great company. They offer three sounds super quiet , stock sound, or earth shaking . I bought the stock sound and I couldn't be happier. I can even listen to the radio. They are nice people and easy to deal with. They offer to send the pipes at a much cheaper shipping rate by not welding the exhaust pipe to the baffles and including sturdy clamps and you can chose to weld ( one seam ) or clamp. I welded mine like factory. The pipe kit is exactly like factory pipes.

 

I have been busy with a new MG project and I have not found pipes for my 67 yet. From what I have read here, it looks like Gardners is probably my best option for stock sounding pipes. For now, I am still using the original GM pipes that came on my car. I am just hesitant to change them out before I hear what new pipes sound like. It seems like I read a lot of posts from folks who buy new "original sound" pipes just to find out that they are very loud. I don't want to spend $2,000 just to find out that they are just as loud as what I have.

Doc

 

Talking about service. I ordered my HiFlow Performance side pipes a week ago and they were on my doorstep today.
Got an interesting email from HiFlow giving me an update on my order. Someone had contacted them to see if they would sell them some of their baffles. Guess what they said!
I guess they are getting their baffles from across the water.
All I have to do now is install them. Hope to do that in the next couple days.
Don

 

Don - I'm only guessing at this but suspect most of the 'pipe manufacturers' depend on overseas components. If they used domestic parts, I think they'd advertise that. I'm still a few weeks away from getting my Gardner side pipes.
Mike T - Prescott AZ

 

I bought a set of High Flow's super quiet. Have not put them on yet.