Stock quiet muffler recommendation.

[Awann99]

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]

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]

I second the Caddy Mufflers

[Steeveedee]

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]

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]

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]

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]

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

[MikeB]

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]

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