Stock quiet muffler recommendation. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Awann99 · 03-01-2021, 02:22 AM

I’ve grown tired of the droning from my turbo mufflers so I want to put something quiet on the truck that will give it that original tinny sound. I have the old exhaust cut off from transmission work so I have the opportunity to run a original single exhaust. Would I see a major difference is gas mileage after running a single? I believe the pipes my local exhaust man uses are 2.5 inches. Any suggestions for mufflers. I was thinking of going with a universal walker 17911.
The truck is running a crate goodwrench 350 195/235 hp,SP2P intake( Yes I know it’s ancient lol) Rebuilt Quadrajet from national carburetors, HEI, sm465, factory open 3.07 gears.
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notsolo · 03-01-2021, 07:17 AM

IMO size of the pipe adds to the noise, OEM pipes would have been closer to 2 ". I don't think there is much difference in mpg. Big Cadillac muffler would be quiet . I have seen a stainless kit, about $800. Y pipe back in an OEM style. If you go with 2 1/2" add a resonator or 2nd muffler it will help a lot...

**Sheepdip** · 03-01-2021, 11:18 AM

I second the Caddy Mufflers

**Steeveedee** · 03-01-2021, 11:49 AM

Vote #3 for the Cadillac muffler(s). Single or dual. One of them muffles a 500 CI engine, so it would not hurt a 350. Also, 2-1/2" pipes are OK, but unless you have manifolds with that size outlet, they don't help all that much. I had a '64 Impala with 2-1/2" outlets, but the tail pipes were 1-3/4", IIRC.

**MikeB** · 03-01-2021, 12:27 PM

I would not go from duals to single unless you can live with less power and poorer fuel mileage. Worst case I would buy some basic stock replacement Walker mufflers and keep the duals. Even then you will lose some efficiency due to the mufflers being "necked down" internally. It's called "restriction" and is one way to reduce exhaust noise.

Quick story: Stock 69 C10 with 307 2bbl, single 2" exhaust, OE-type muffler, and 1-7/8" tailpipe. It got 10-12 mpg all around driving. Went to 2" duals with turbo mufflers (that actually weren't too loud) and mileage jumped to 12-14. And I can't begin to describe how much more power the engine had. With stock exhaust, it sounded like it was laboring to maintain 60 mph. With dual exhaust, it was like it got a shot of an asthma inhaler!

I just remembered this: Back in the day, it was common knowledge that a 250hp/327 4bbl with dual exhaust would get better fuel mileage than a 195hp/283 2-bbl with single exhaust. Of course, that was if your right foot behaved responsibly! In addition to the benefits of dual exhausts, the 4bbl primary venturis were smaller than the 2bbl venturis for better efficiency.

BRL · 03-02-2021, 03:29 AM

I had 2 Flowmasters dumping just behind the cab and that got annoying pretty quick.

Went to a Walt's Muffler shop and my friend's brother installed a 2 1/2" dual exhaust with a balance tube in between, that dumps behind the axle.
(I'm running headers too)

Don't know what kind of mufflers, but the first time I fired it up I had to ask if the motor was running!

Awann99 · 03-02-2021, 06:39 AM

Lots of good info. Thanks fellas. I think I will stay with the dual exhaust then but add the crossover pipe and use the Cadillac mufflers. It looks like walker makes a few of them.

71longbed-brew · 03-02-2021, 11:23 AM

i went with these when i was tired of my glasspacks
https://www.amazon.com/Walker-18106-...78187676&psc=1

**MikeB** · 03-02-2021, 11:45 AM

Quote:

Originally Posted by 71longbed-brew

i went with these when i was tired of my glasspacks
https://www.amazon.com/Walker-18106-...78187676&psc=1

FYI, that part number is 2-1/4" in and out.

jimijam00 · 03-02-2021, 08:37 PM

2.25 pipe with the longest walker oem replacement case muff you can fit under there.

03-01-2021, 02:22 AM	#1
Awann99 Registered User Join Date: Jan 2018 Location: TN Posts: 263	Stock quiet muffler recommendation. I’ve grown tired of the droning from my turbo mufflers so I want to put something quiet on the truck that will give it that original tinny sound. I have the old exhaust cut off from transmission work so I have the opportunity to run a original single exhaust. Would I see a major difference is gas mileage after running a single? I believe the pipes my local exhaust man uses are 2.5 inches. Any suggestions for mufflers. I was thinking of going with a universal walker 17911. The truck is running a crate goodwrench 350 195/235 hp,SP2P intake( Yes I know it’s ancient lol) Rebuilt Quadrajet from national carburetors, HEI, sm465, factory open 3.07 gears. Posted via Mobile Device Attached Images

03-01-2021, 07:17 AM	#2
notsolo Registered User Join Date: Apr 2008 Location: Md Posts: 2,482	Re: Stock quiet muffler recommendation. IMO size of the pipe adds to the noise, OEM pipes would have been closer to 2 ". I don't think there is much difference in mpg. Big Cadillac muffler would be quiet . I have seen a stainless kit, about $800. Y pipe back in an OEM style. If you go with 2 1/2" add a resonator or 2nd muffler it will help a lot... __________________ http://67-72chevytrucks.com/vboard/s...d.php?t=635605

03-01-2021, 11:49 AM	#4
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,724	Re: Stock quiet muffler recommendation. Vote #3 for the Cadillac muffler(s). Single or dual. One of them muffles a 500 CI engine, so it would not hurt a 350. Also, 2-1/2" pipes are OK, but unless you have manifolds with that size outlet, they don't help all that much. I had a '64 Impala with 2-1/2" outlets, but the tail pipes were 1-3/4", IIRC. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-01-2021, 12:27 PM	#5
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,599	Re: Stock quiet muffler recommendation. I would not go from duals to single unless you can live with less power and poorer fuel mileage. Worst case I would buy some basic stock replacement Walker mufflers and keep the duals. Even then you will lose some efficiency due to the mufflers being "necked down" internally. It's called "restriction" and is one way to reduce exhaust noise. Quick story: Stock 69 C10 with 307 2bbl, single 2" exhaust, OE-type muffler, and 1-7/8" tailpipe. It got 10-12 mpg all around driving. Went to 2" duals with turbo mufflers (that actually weren't too loud) and mileage jumped to 12-14. And I can't begin to describe how much more power the engine had. With stock exhaust, it sounded like it was laboring to maintain 60 mph. With dual exhaust, it was like it got a shot of an asthma inhaler! I just remembered this: Back in the day, it was common knowledge that a 250hp/327 4bbl with dual exhaust would get better fuel mileage than a 195hp/283 2-bbl with single exhaust. Of course, that was if your right foot behaved responsibly! In addition to the benefits of dual exhausts, the 4bbl primary venturis were smaller than the 2bbl venturis for better efficiency. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

03-02-2021, 03:29 AM	#6
BRL Registered User Join Date: Jun 2014 Location: Tahuya WA Posts: 620	Re: Stock quiet muffler recommendation. I had 2 Flowmasters dumping just behind the cab and that got annoying pretty quick. Went to a Walt's Muffler shop and my friend's brother installed a 2 1/2" dual exhaust with a balance tube in between, that dumps behind the axle. (I'm running headers too) Don't know what kind of mufflers, but the first time I fired it up I had to ask if the motor was running!

03-01-2021, 11:18 AM	#3
Sheepdip Senior Member Join Date: Nov 2018 Location: Waterford California Posts: 2,634	Re: Stock quiet muffler recommendation. I second the Caddy Mufflers

03-02-2021, 06:39 AM	#7
Awann99 Registered User Join Date: Jan 2018 Location: TN Posts: 263	Re: Stock quiet muffler recommendation. Lots of good info. Thanks fellas. I think I will stay with the dual exhaust then but add the crossover pipe and use the Cadillac mufflers. It looks like walker makes a few of them.

03-02-2021, 11:23 AM	#8
71longbed-brew Registered User Join Date: Sep 2008 Location: Salem Oregon Posts: 64	Re: Stock quiet muffler recommendation. i went with these when i was tired of my glasspacks https://www.amazon.com/Walker-18106-...78187676&psc=1 __________________ 350/th350 DNA (Chinesium) Heads Performer Intake 1905 AVS2 Edelbrock 3.42 Eaton Posi

03-02-2021, 08:37 PM	#10
jimijam00 Registered User Join Date: Apr 2009 Location: PNW Posts: 553	Re: Stock quiet muffler recommendation. 2.25 pipe with the longest walker oem replacement case muff you can fit under there.



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