Building a quiet, low restriction exhaust for a big block

Starting to rework a 77 d150 with 440. I’d like a quiet ride, close to modern exhaust standards. That is without the modern cost. I looked on rock auto and for example a new age challenger muffler is like 1k-1500. Yikes.

That model 440 is pretty much a dog so I can’t be corking it up with restrictions to accomplish this unless I want to play little engine that could going up hills.

Thinking I’ll have the manifolds to start, as it has so many needs and I also dont want to capture the starter. I just don’t have the time I used to for taking all sorts of extra stuff off for simple repairs. Even if a set of headers is available that doesn’t capture, the cost would hurt things like getting a paint job.

Will run an x pipe as that has always suited me.

First thoughts are big mufflers and then also use a can type one near the back. That should cut out a drone, not sure it will be quiet enough. I could try a second set of mufflers before the cans, but would that be the ticket? Real estate might be a problem to since it all has to run down the pass side.

Will finish with repop road runner/super bee tips out back.

Mufflers, then some resonators downstream. Use 2.5" pipes.

Yes, will be 2.5

Any particular kind or brand of muffler or resonators?

I used some cheap parts house "cherry bomb" glasspacks as the only muffs on a truck DD. they worked but did get louder over time. In their favor was that they did not neck down where the end nipples are welded to the main case & the louvers were punched outward, both for no restriction. In your case I would get the longest pair I could find or even 2 pair of em with or with out some dynomax regular type muffs. best would be a quiet restricted system with some electric or vac or cable cutouts right at the header collectors, not cheap tho & would be quiet when you need quiet & loud only when you want it.

I just put some 2.5" $40 stainless mufflers on my 5.0 Mustang that fit your description perfect....they are essentially glass packs but are not straight thru they are rectangular and the pipe is offset from one side to the other as it goes thru the muffler. They are not loud, but have a nice sound.
https://lmr.com/item/JES-MF1236/Jones-Max-Flow-Performance-Muffler

I think my old '73 Power wagon used dual 2.5" offset inlet, center out turbo style mufflers mounted side-by-side with the inlet on the low side and center up higher before going over the rear axle. It was not really loud, but you could still hear it.

My '86 W100 with a 318, I think used 2" flare at manifolds that up sized to 2.25" right after the manifold connection, then used (I think the brand was IMCO?) chambered muffler and I think it was a 3" in, 2.25" out, but we mounted it backwards with the 2.25", and a single 3" out, over axle and exiting under the bed side behind rear wheel at a 45 degree angle, end cut parallel (45 degree) to the bed side. Not sure if that hurt flow, but it made a near stock 318 sound pretty good.

There are 3" in, and 2.5" out mufflers that might work good reversed. It sure makes a simpler install with just the single 3" tailpipe.

I used the Jones mufflers on several vehicles and love them, nice and quiet with minimal restrictions. I think they discontinued the unpolished version so plan to spend a few bucks more.

I also agree with the dual inlet single outlet idea, just way easier. You won't lose any performance from that.

Thanks guys, lots of stuff I haven’t used or heard of to research.

I do want a dual exit look though.

What kind of power are you talking? If you are talking a stockish 1977 440 and you want quiet, you don't need 2.5" dual exhaust. The best driving, snappiest throttle, best pulling 440 I ever had was a factory original 350 hp 440 in a 67 Chrysler. It had a 2.5" single exhaust.

If you are like most, and simply must have an exhaust system that is 50% bigger than you need, get a dual system with 2.5" headpipes, necked down to 2.25" mufflers and 2.25" tail pipes. Get the longest full body muffler that will fit from Midas. This is basically what the factory used on the highest hp 440 it offered. This will support an honest 375 hp.

I've made over 400 hp with that system with a DynoMax full body (25.5" long) 2.25" Super Turbo muffler (17747).

In the future you can step up the muffler and tail pipe size to 2.5" and easily support +450 hp.

You would probably be better dropping it down to a 2.25 which if memory serves is the exhaust outlet size on the regular lo-po stock exhaust manifolds.

Get the longest muffler you can. Larger mufflers reduce noise more. If you get a regular oval style chambered muffler, get an offset in/offset out. Center inlets or outlets restrict exhaust flow considerably unless the muffler is a straight through design like a dynomax ultra flow.

I like "Turbo" mufflers for reduced restriction and reasonably quiet. They are pretty quiet at cruise and a little bellow with heavy throttle. For quiet with minimum restriction, use the largest size you can fit.


Dynomax makes a nice turbo. Also lots of others. Your local AP store likely has a good low cost option.

The Dynomax "Super Turbo" seems to be the best-flowing of that style, has flow directors at the inside ends & doesn't neck down inside. Good crisp sound, not boomy, very livable with tailpipes.
A buddy ran a pair of Imperial mufflers on a SB Chevy PU and it was quiet, about like a stock dual exhaust from the '60s. Ran stronger than stock.
I'd go with 2.5" downpipes if the manifold flanges accept them, H or X pipe, 2.5" mufflers, 2.25" tailpipes to the rear corners.

2.25 would cut some sound, but hymn me in for future upgrades. Both engine rebuild and just adding headers.

Kinda a curious response. Dyno tests of back to back same engine with just bigger exhaust shows you gain power everywhere with larger pipes that the myth holds as “being bigger than you need.” Also guys like ray evernham will tell you to step your exhaust size bigger as you go. A bean counter will tell you it’s “good enough” for what your doing if you can cut a few cents out of a trillion cars and make packaging easier on an assemble line.

There really is a lot to be gained by putting on a big honking exhaust. I can think of a couple cars it really stood out on after switching what should’ve been an ok setup. I just have never one together with being quiet as part of the package. Some things came out fairly tame, others roared. Last car I did ended up with a drone around 2500. Sold it before I got around to trying resonators.

I've done Dynomax Super Turbos and Ultra Flows on different cars. Both worked really well.

Ultra flow with 3" pipe is what I run now.

Check out the Dynomax Super Turbo Muffler # 17789 which is 3" dia,
I also think they make it in a 2 1/2"

I have a 77 D150 with a 440 as well. I have headers on mine and because of where the fuel tank is located, I had to run the left side pipe across and down the right side to clear the tank. I would love to run an x or h pipe in the system, but find it difficult to do so because of how the pipes are configured. You might get away with running a pipe inside of the tank when using manifolds, but unless you have a rear mounted tank, (i.e. Ramcharger style) you'll have a tough time running headers without running the left-hand pipe across like I had to.

Maybe its how you look at the tests. I usually don't see the same. And tests are usually done with higher hp applications.

I have track times and dyno info to support it all. If you think your at 450 hp now, and what to go to 600, go bigger.

The 2.25 will be noticeably quieter than the 2.5". I've gone high 12s at 109 in a 4250 lb car with 2.25" mufflers

The Engine Master engine exhaust testing pretty much supports what I have learned. In that test the 2.5" system gave up like 15hp over a 3" system on a 600 hp+ engine. What is your power level, 250 ish?

What you are looking for in that 440 isn't in the exhaust.
You need to remove any smog equipment, add a good carb. a torque cam and converter, proper rear gears. Add some compression and your GOLDEN.

You want quiet?
Go stock replacement.
Bigger may be sound like more fun, but isn't necessary for your needs.
Same for fancy mufflers. Stock replacement will work fine.
That 440 should have loads of torque on tap.
That's what your looking for, right?
You can do a y pipe in front of the rear axle for the dual look you want. It won't help performance though.
Any competent muffler shop should be able to accommodate you.

If you want quiet, keep the pipe diameter as small as possible and go as long as possible on the muffler.

20" bodied Dynomax Super Turbos. Don't use "stock" mufflers.

I’d like to look at it up on a rack and lay the system out. Might be hard to stack anything other than bullets, so solution might be a y pipe into a single big muffler and split from it.

Anybody try a Flowmaster 50 or 70 series on a big block? I got to thinking about 20 years ago I put a system of theirs on a 94 f150 5.0 and it was quiet. Believe it was a force II and it had a 70 series. Pretty hard to compare a single pipe on a 302 to this deal. That and I sold that truck 15 years ago so I can’t remember exactly how it sounded.

I've got FlowMaster 50s on 2 cars.
My '62 NY stationwagon, with a stock 413ci engine and 2-1/4" dual exhaust, is very quiet.
But its engine burns some oil and it has deposited the soot mostly in the (some 15 year old) mufflers which toned them down very nicely.

Thinking I could copy the sound into my '65 300 convertible with a 400ci with 2.5" dual exhaust and an 'advanced' cam, and it turned out to be fairly loud.
It has the newest of the bought Flowmasters. Has a nice rumble while driving and idling, but is very loud when cold. Actually a bit unsuitable for the car.

My '60 NY with 496ci engine has Dynomax mufflers but I had to add bullet style resonators at the rear to tone them down a bit. But they are still very noticable.

Where are you at? I've got a pair of Flow Master 70 series mufflers that have never been installed in the rafters of my garage. They're huge. 2.5" inlet/outlet that are both off center.

How about a y-pipe into a single 3" super turbo round long welded muffler with a 3" off the shelf v-10 tailpipe? Quiet, cheap and works with a bigger engine than yours.

Dynomax Super Turbos 17748 or 17749 depending on what fits better. They are 2.5" and flow well. Use an X or H pipe and use some more mufflers as resonators.
That's where a long glasspack is helpful.
If you do have to go to single tailpipe it has to be 3". By the time the exhaust has gotten to the back axle it has cooled and contracted some. Huge isn't so necessary back there.
R.

I’m in cincy. I don’t have the truck to see how much room I have under there. It’s getting rubber parts replaced at a shop and a general going over.

Have considered I might have to do a y pipe and maybe split at the muffler. Suppose I could run a faux tip to get the look, seems a hokey thing to do.

Just do it!!!

Super Turbo's on everything I have/had in the last 20 + yrs,only drawback is my 62 Savoy wagon,complete Max Wedge system all 3" and it is louder than I like but still the quietest 3" performance muffler out there so I live with it.