What 3” muffler has the following characteristics:

[Extended Power]

Installing a nasty 572 into my ‘70 GMC.
I’m going for the “Show ‘n Go”
With the custom Lemon’s headers I had built for my truck, the old Flowmaster 40, 2 1/2” exhaust was removed.
Going 3”
I’m not looking for ANYTHING that “brap’s”
Cab drone should be minimal.
Looking for a wicked idle sound, that will showcase the engine’s performance.

All the videos I’ve watched have shown idles, but no hard acceleration.

Borla XP
Borla XR 1
Flowmaster 40’s again? (Sounded good with the old big block, no brap.)

What are some of your opinions, or what have you used, that you would do again, or not ever again?

[Sheepdip]

I installed Flowmaster Super 40's on my 40 Coupe 350/350/2500 stall, and couldn't be happier with the sound and tone. I get asked all the time what mufflers I'm running. The cams not a real polluter just a little tight lope to it.
I was at March Meet in Bakersfield several years ago and asked at the Flowmaster Booth as to their most popular muffler sold. The guy didn't even hesitate "Flowmaster Super 40"

[Extended Power]

Originally Posted by Sheepdip

I installed Flowmaster Super 40's on my 40 Coupe 350/350/2500 stall, and couldn't be happier with the sound and tone. I get asked all the time what mufflers I'm running. The cams not a real polluter just a little tight lope to it.
I was at March Meet in Bakersfield several years ago and asked at the Flowmaster Booth as to their most popular muffler sold. The guy didn't even hesitate "Flowmaster Super 40"

May just stay with them, as I had no problems with the way they sounded at idle, or wide open.
Thanks!

[72SB]

Exhaust note is subjective to each person...with that said a "chambered" muffler like the FM 40 is the typical "muscle car" sound. However, drone, especially if pipes do not exit rear of truck, and cab exhaust noise for some is an issue. I find as I age this can be annoying for 99% of the driving I do.

The FM 50's are a little tamer. Spintech is also a chambered muffler.

FM has recently come out with the "FX" which is a straight through muffler like the Magnaflo and straight through Dynomax (not turbo) with the perforated straight through tube wrapped in fiberglass. I just pulled my 40's off my 67 Camaro when I put in my 355 with headers as the interior noise was too much. They have quite the nice note and are louder than the Magnaflo or Borla counterpart

here is a chart listing all the FM mufflers relative to how loud.

https://www.holley.com/brands/flowma...flowfx_series/

[Extended Power]

Originally Posted by 72SB

Exhaust note is subjective to each person...with that said a "chambered" muffler like the FM 40 is the typical "muscle car" sound. However, drone, especially if pipes do not exit rear of truck, and cab exhaust noise for some is an issue. I find as I age this can be annoying for 99% of the driving I do.

The FM 50's are a little tamer. Spintech is also a chambered muffler.

FM has recently come out with the "FX" which is a straight through muffler like the Magnaflo and straight through Dynomax (not turbo) with the perforated straight through tube wrapped in fiberglass. I just pulled my 40's off my 67 Camaro when I put in my 355 with headers as the interior noise was too much. They have quite the nice note and are louder than the Magnaflo or Borla counterpart

here is a chart listing all the FM mufflers relative to how loud.

https://www.holley.com/brands/flowma...flowfx_series/

I’m 54 this summer, so the sound of brapping turkey shooters, is not my thing at all.
But an almost mechanical sound of the engine, exiting the exhaust, as its poppin off the lope of the cam, is music to my ears.

[72SB]

I have drag raced for as long as your age. I to like the "real" sound of a camed engine.

If you are happy with the 40's now, stay with them. Consider a X pipe pre mufflers

If you want max sound, just go with dumps right after mufflers. Of course there is always cutouts

[pjmoreland]

This is a fairly decent video from Flowmaster:

https://m.youtube.com/watch?v=JcqJmwaDfYE

I've had 40-series mufflers on a couple of trucks. I ended up going with the 50-series Delta Flow this time around to tone things down a bit. The idle is definitely tamed down and sounds less like a speed boat, as my neighbor said.

[72SB]

Chambered mufflers generally offer a more aggressive idle sound which varies from chamber design itself

Straight Thru mufflers generally are quieter than chambered at idle but louder at WOT and typically provide more HP than a chambered muffler.

Larger pipe size often increase top end HP but gives up some low end TQ

Obviously what I like may not be what someone else likes and vice versa.

The FM chambered mufflers brought out in 60's is the "classic" muscle car sound. Not necessarily the highest HP muffler

Engine Masters has done comparison testing on HP/TQ and decibel readings at idle and WOT on all the muffler types. Turbo type making the least HP but mellow sound

[doug_p]

There is a vid on YouTube of a guy with Spintech 6000's (I think its those) on a single cab Silverado w/3" inch exhaust w/ a cam headers (Frankenstein Heads) etc. Talks about it sounding like a Corvette - which I would agree, it sort of does. Check it out, might give you an idea of what the Spintechs sound like anyway.

[truckster]

I just put Magnaflow 14" mufflers on mine and I love the sound.

[D.B]

My 72 C20 with a built 600hp 511 big block runs through large tube tri-y headers in to 3" Pypes exhaust system that has an "H" pipe, Cut-Outs and FM 40's. The system runs out back and dumps right at the bumper so the tips are hidden. The roller cam is over 600 lift with over 300 duration so it does have a lumpy idle. It sounds great, has a really nice rumble at idle with an even better exhaust sound at mid to wide open throttle.

[KQQL IT]

I have a pair of 70 series on my 73

[jumpsoffrock]

PLEASE post pics of the 572 installed when you're done. What a dream truck

[Joyridin]

I put SpinTech mufflers on mine with a 3" exhaust. They sound pretty good and have a pretty hefty deep rumble. There are a lot of different version, but after running Flowmasters on a few cars in the past, I was trying to get rid of the drone.

[Already Gone]

Hi used Dynomax Super Turbos, " Part # 17747 ", with 2 1/4 pipes from the ram horn manifolds on my stock 350 4bbl 72 C10 right to the back exiting to the side 1/2 way from rear tire to rear bumper. The mufflers are 24 inches overall length and the muffler itself is 20 inches long. Nice idle sound and no cab drone and I've had no carpet last 2/3 years. I looked up the part numbers for 3 inch Super turbos about closest to the same lengths as mine and they are 17698 & 17769. I have videos of mine idling and if want to hear send me a PM with an email address and I'll send to you as can't post videos here.

https://www.dynomax.com/mufflers/super-turbo-mufflers

[Richard]

Originally Posted by KQQL IT

I have a pair of 70 series on my 73

+1 If you like the classic Flowmaster sound and do not want the annoying loud noise of 40-50 series get them. Most avoid because of greater cost. Get kind remarks on the single 3" 70 series in my 94. Inclined to use two with an x-pipe on my current build. Nice sound at idle and not to loud when at full throttle. A 60's LS swap van at the shop with a flow 40 is really loud, pop's and crackles even at idle. Personally, I hate it. If that is what you want, go for it.

[Killer Bee]

3" inlet / 3" outlet single chamber flowmasters under my 550hp 469 Poncho powered GTO

sounded like 55gal drums - DEEP!

tolerable sound level mid throttle cruising power but whack the go pedal and look out!

and not even a whiff of that fart can stench

had a base renta-cop hassle me a few times so I tried corking it up with standard 'turbo' style mufflers - couldn't keep gaskets

some months later got pulled over on base doing nothing, but this guy just wanted to check it out.. insisted I do a burnout in the parking lot - of course I obliged

most name brand high performance muffler companies have u-toob videos of their products in various output engines..

and of course cruise nights just about anywhere - stop and look what's under the ones you like the tunes from

btw, back then they didn't have the tube bending abilities they have now, mine dumped right in front of the axle..

in a truck you may have more options - good luck!

[KQQL IT]

Also will add if it ends up having a drone.

Look up a J pipe or hemholtz resonator.

[70cst]

Spintech on a 402BB

https://www.youtube.com/watch?v=K1LXf66LGaY