Advice on Muffler Replacement

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OldBlueDually

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Well, sure am glad I found this thread, instead of starting a new one.

I am debating between two mufflers (Flowmaster Super 44, or Thrush), one of which I do have experience with (Thrush).

The mufflers will be going on my 76 GMC crew. Right now it has 3" duals on it and Smitty mufflers. I plan to run 3" with a Flowmaster 44 or Thrush.

The engine is a 455 Olds, with a mild thumpr cam. I want that hot rod sound. I had a set of Thrush mufflers on my 99 GMC Sierra Classic and they sounded great, even for a stock fuel injected engine.

However, I have heard many videos of Flow Super 44's, and I really dig the sound. I drove a beautiful 72 Chevell with a 468 BBC in it that had flowmasters, and it sounded heavenly.

However, as mentioned before, flowmasters are twice the price of Thrush. The Olds engines have a really deep grumble to begin with, more than the BBC, so I "think" if I put Flowmaster super 44's on it that this engine should sound pretty dang good.

The mufflers will be located below the cab area I assume, pipes will exit prior to rear wheels. I will be insulating the interior of the truck.

Thanks in advance for any advice!!!
 

Vbb199

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Well, sure am glad I found this thread, instead of starting a new one.

I am debating between two mufflers (Flowmaster Super 44, or Thrush), one of which I do have experience with (Thrush).

The mufflers will be going on my 76 GMC crew. Right now it has 3" duals on it and Smitty mufflers. I plan to run 3" with a Flowmaster 44 or Thrush.

The engine is a 455 Olds, with a mild thumpr cam. I want that hot rod sound. I had a set of Thrush mufflers on my 99 GMC Sierra Classic and they sounded great, even for a stock fuel injected engine.

However, I have heard many videos of Flow Super 44's, and I really dig the sound. I drove a beautiful 72 Chevell with a 468 BBC in it that had flowmasters, and it sounded heavenly.

However, as mentioned before, flowmasters are twice the price of Thrush. The Olds engines have a really deep grumble to begin with, more than the BBC, so I "think" if I put Flowmaster super 44's on it that this engine should sound pretty dang good.

The mufflers will be located below the cab area I assume, pipes will exit prior to rear wheels. I will be insulating the interior of the truck.

Thanks in advance for any advice!!!


Flowmaster all the way
 

OldBlueDually

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That is what I am leaning towards. I think those hooked to this exhaust and that engine would sound nice. Still debating to leave my stock exhaust manifolds or go with headers on it. I can always change that later too....
 

Craig 85

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The Olds 455 has the best sound even with stock manifolds. I'll never forget the sound of my friend's '68 Hurst/Olds.

I went with the Super 40's as they have a larger case (5" vs. 4") than the Super 44. Post #18.
 

Rusty Nail

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I like Flowmaster 40 series.

Some advice is to put the mufflers under the bed (not under the cab) and connect both sides with an H or crossover, and use tailpipes that exit out the back or sides, not toward the ground.

And take pix next time eh?sheesh!

If the price is an issue, you can run these Summit branded chambered mufflers.

Those arent a terrible option - ive heard some...neither are salvage yard Flowmasters like mine .:waytogo:

Gonna need some pix tho not playin. ;)
 
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choate

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Catbox

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Noted: Photos for @Rusty Nail attached.

So on my 1995 Sub with a 3 inch single exhaust I have run a Flowmaster 40 series muffler for the last 17 years.
It has some cracks and is showing its age for sure and the tailpipe should have been changed ages ago....
You must be registered for see images attach


I replaced that with a single Jones Flow Pack 3 inch single chamber muffler, same as what I have on my squarebody. I also sourced a 3 inch mandrel bent junkyard tail pipe that was near new when I found it for $12. But the muffler was just not producing the right sound coming out from my Suburban.
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Change is needed.
I found the Flowmaster I wanted the boy to order up as it was a center in / center out design and the easiest thing to put in out in the driveway.
It is a Flowmaster Super 44 3 inch in / out muffler.
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It is a deeper sound than the standard 2 chamber 40 series, so it is not quite the same sound out of the Sub.
But it is far closer than the single chamber.
At this time I had also found a tip that I liked that matched the muffler, so we ordered that up and @Maxwellvis welded that on as well.

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Rusty Nail

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Great job man, thanks!

I had really high hopes for the Jones muffler you got , certainly described as interesting! Disappointed to rear suck a lackluster review.

There's not video by chance - o_O is there?
 

Craig 85

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I don't like the rap sound of straight through mufflers. I'm debating about going with a pair of 50 series stacked vertical to replace the dual in/out in my 8.1L Suburban 2500.
 

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@OldBlueDually You want hot rod sound, go with glasspacks. Long glasspacks have a nice sound, and can add short glasspack upstream or downstream as a resonator if you want a slightly more mellow tone. On my '81 I did this and it sounds great.
 

Rusty Nail

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Ya know, while we're talkong about it...I replaced the resonator in my Civic with an M80 glasspack. (Short)
Having it installed a couple of months now...sometimes I find myself wanting a longer glasspack instead of the shorter one BEFORE the muffler.
 

SirRobyn0

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I like Flowmaster 40 series.

Some advice is to put the mufflers under the bed (not under the cab) and connect both sides with an H or crossover, and use tailpipes that exit out the back or sides, not toward the ground.

And take pix next time eh?sheesh!



Those arent a terrible option - ive heard some...neither are salvage yard Flowmasters like mine .:waytogo:

Gonna need some pix tho not playin. ;)

So all good advice starts out with I read the beginning of the thread and the end of the thread but nothing in between right? Anyhow that's me I did some skimming and saw the above post and wanted to make a few comments.

Assume for the sake of discussion we are using the same muffler in all the configurations I'm about to mention.
Mufflers under the cab with no tail pipes or turn down dump under the truck will be the loudest on the inside. Mufflers under the bed with side exits before the rear wheels will be a little quieter, mufflers under the bed with pipes exiting the sides behind the bed will be quieter, while mufflers under the bed with pipes coming straight out the back will be the quietest. An H-pipe does not really make the exhaust quieter, but it makes the sound more even which results in sound that you will perceive as quieter even though it's really not. There are so many benefits to H-pipe, I cannot really see any reason not to have one other than possibly initial cost.
 

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Great job man, thanks!

I had really high hopes for the Jones muffler you got , certainly described as interesting! Disappointed to rear suck a lackluster review.

There's not video by chance - o_O is there?

It was not that it was a bad sounding muffler, it is just not how my sub sounded before.
So it was not right to my ear.
Here is a ****** startup of the sub with the Jones muffler under it.

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The 454 in the truck wears a pair of the 3 inch Jones Flow Packs and it sounds pretty good.
In this video it still has the stock exhaust manifolds on it.
Now the truck has a set of Chevelle long tube headers on it and it sounds even better, but no video of that currently.

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Catbox

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@OldBlueDually You want hot rod sound, go with glasspacks. Long glasspacks have a nice sound, and can add short glasspack upstream or downstream as a resonator if you want a slightly more mellow tone. On my '81 I did this and it sounds great.

Since @Rusty Nail has me with the video clips...
Here is a short video of my 1954 Bel Air 235 straight six with split exhaust and true duals.
It has the cutest little 12 inch cherry bombs in the tiny exhaust pipes...

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