Dual exhaust on a 4x4?

[Vintage Windmills]

I'm looking for mufflers for my K20 and will be going with dual exhuast with one pipe out each side so it looks as close to stock as dual exhaust can. For example, when you're on one side, you just see one pipe sticking out.

Question 1: what fits best for the typical oval mufflers? I see there are offset inlet/offset outlet, inline inlet/outlet, offset one/inline other, etc.

Question 2: what is the quietest with good performance and quality? I've heard good things about Magnaflow.

Question 3 (request): Please post pics of dual systems on a 4x4. I'd like to see how the piping and mufflers are positioned.

Thanks in advance.

Jud

[jasons]

My Blazer has mufflers with an offset. They are lifetime mufflers from Midas and they are as quiet as a stock system would be. The exhaust was installed just over 10 years ago and one muffler finally needed to be replaced last fall. I've got the engine out now If you want I can try to post a couple photos of how it is routed.

[budman k20]

Jud,
I bought a set of 2.5 tailpipes that exit out each corner at an angle (stockish) for my k20 the pipes were made in MN. But I can't remember the name of the company (it is a big name brand). I think you can get a complete set if you want. I have headers and a crossover pipe on mine so I just bought the tail pipes. I will look tonight for a invoice or name for you.
I did research these mufflers and they flow very well and sound very mellow Google this Muffler: Walker / Dynomax (2) PN/17748 Cost for 2 $103.90
I found some test results that put these near the top for not loosing HP. I have a high compression 406 sbc with 450 hp so they would be quiet on a near stock engine.

Bud

[Vintage Windmills]

Originally Posted by jasons

My Blazer has mufflers with an offset. They are lifetime mufflers from Midas and they are as quiet as a stock system would be. The exhaust was installed just over 10 years ago and one muffler finally needed to be replaced last fall. I've got the engine out now If you want I can try to post a couple photos of how it is routed.

Pics would be great!

[sboris]

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[jasons]

Here are a few pictures of my exhaust.









I have the stock 4x4 ramshorn manifolds that exit straight down.

[FirstOwner69]

Here are a couple links that may be of interest. Heartthrob Exhaust is in Litchfield, MN. That may be the company that budman k20 was thinking of (post #3). I bought their system for my 69 C20, but have yet to start the engine as the project is still in progress. I think this is the brand LMC sells.

The system is for stock manifolds. The 2-1/4" pipes appear to be high quality aluminized steel and are mandrel bent. The mufflers for the 2WDs mount on edge, narrow side down, as they did from the factory. Not sure of the 4WDs. You have a choice of no mufflers, glasspacks or stock mufflers which, if I recall correctly, are by Maremont. The pipes exit either behind the rear wheels or out the back depending what you specify.

Heartthrob's catalog (see page 13):
http://heartthrobexhaust.com/67432%2...log%202011.pdf

Auto Accessories Garage (where I bought mine at 10% off for new customers and free shipping... LMC charges about the same PLUS truck freight):
http://www.autoaccessoriesgarage.com...Exhaust-System

[72 Super]

I just had the exhaust done on my 1972 4x4. I went the stock ramhorns with the Magnaflows. They have a great tone and aren't too loud either, very happy. When I got the truck it had headers and Flowmaster, It was really loud.

[1967gm4x4]

I had 2 1/2 inch put on my 67 and that was about the biggest I would go because it gets pretty tight around the transfer case, I just put flowmaster 40 series center in center out and it all wound up fitting good I just put the mufflers so they were straight up and down for more clearance if that makes any sense.
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[1967gm4x4]

And the mufflers sound just right with a 402 bbc not too loud or to quiet, I have heard a lot of good things about the dyno max bullets to, the dyno max oval mufflers make a very nice bassy deep tone also.
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[Vintage Windmills]

Originally Posted by budman k20

Jud,

I did research these mufflers and they flow very well and sound very mellow Google this Muffler: Walker / Dynomax (2) PN/17748 Cost for 2 $103.90
I found some test results that put these near the top for not loosing HP. I have a high compression 406 sbc with 450 hp so they would be quiet on a near stock engine.

Bud

Bud, is the inlet centered in the mufflers and is the outlet centered? I will check those out.

Originally Posted by jasons

Here are a few pictures of my exhaust.

I have the stock 4x4 ramshorn manifolds that exit straight down.

I'm running the stock horns and 2.5 as well but may end up running 2.25 downpipes for lower end torque then 2.5 out back.

Same question for you also, is the inlet centered in the mufflers and is the outlet centered?

Originally Posted by FirstOwner69

Here are a couple links that may be of interest. Heartthrob Exhaust is in Litchfield, MN. That may be the company that budman k20 was thinking of (post #3). I bought their system for my 69 C20, but have yet to start the engine as the project is still in progress. I think this is the brand LMC sells.

Great info, I'll check it out. Do you know if mufflers are aluminized steel as well?

Originally Posted by 72 Super

I just had the exhaust done on my 1972 4x4. I went the stock ramhorns with the Magnaflows. They have a great tone and aren't too loud either, very happy. When I got the truck it had headers and Flowmaster, It was really loud.

That is exactly what I think I'm going to do! I listened to a couple maganaflow setups behind 350's today on youtube and they sounded quiet until they got on it then had a nice tone, but weren't too loud. Same question for you also, is the inlet centered in the mufflers and is the outlet centered? Are you running 2.5 all the way?

[Vintage Windmills]

Originally Posted by 1967gm4x4

And the mufflers sound just right with a 402 bbc not too loud or to quiet, I have heard a lot of good things about the dyno max bullets to, the dyno max oval mufflers make a very nice bassy deep tone also.
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Cool, here is a video of the oval ones. They sound really nice but louder than the magnaflows so I think I'm still leaning towards the magnaflows. https://www.youtube.com/watch?v=rXtHSAU-NSY

Magnaflow video. Wonder if he has cats and if they make it more quiet? Otherwise pretty much the same engine as mine (vortec 350).

This one probably doesn't have cats but he has a lopier cam. A little louder but still not bad. Skip ahead to 2:40 to listen

[jasons]

Originally Posted by Vintage Windmills

I'm running the stock horns and 2.5 as well but may end up running 2.25 downpipes for lower end torque then 2.5 out back.

Same question for you also, is the inlet centered in the mufflers and is the outlet centered?

My mufflers are offset. The inlet is next to the frame and the outlet is on the opposite side near the drive shaft.

[budman k20]

My mufflers are offset and Heartthrob is the company that made my tailpipes. I have magnaflow on my trans am and it is quiet until you get on it. But I think the dynomax's are more quiet. I did listen to the y-tube video and it did sound loud!

[RHGuyettejr]

Here are some pics. LMC exhaust system, it is actually pretty good quality and fit well with no modifications. Hanging it is a bit tricky, but they send you a ton of hardware. Basically a temp setup until the truck is restored so I can move it around.







I checked into the mufflers, forget the name now but they where American made and cost about $25 a piece.

[Ol Blue K20]

I would go to a quality exhaust shop tell 'em what you want and get 'er done

[Vintage Windmills]

Originally Posted by Ol Blue K20

I would go to a quality exhaust shop tell 'em what you want and get 'er done

I'm planning to dyno the engine before its in the truck but we need to have the right exhaust on there. I am mocking up the system with downpipes, and straight sections for now but want to use the actual mufflers I'm going to use so I need the mufflers now and will fit the system and weld together later.

[Ol Blue K20]

Interesting, but now I understand why. I had never thought about that.

[Vintage Windmills]

It looks like offset to the frame rail on the inlet and offset to the driveshaft on the outlet is the way to go.

[Mike C]

Having done several exhausts over the years on the Jimmy, I have settled on what I think is the best. 2 1/2" Corvette manifolds, 2 1/2" aluminized pipe using DynoMax Hemi Turbo mufflers. Looking at CFM #'s that DynoMax supplied, they were very efficient in addition to being quiet.

I replaced a set of Heddman Hedders and a 2 1/4" exhaust with Turbo King mufflers and this system beat it in every way.

[72 Super]

Originally Posted by Vintage Windmills

That is exactly what I think I'm going to do! I listened to a couple maganaflow setups behind 350's today on youtube and they sounded quiet until they got on it then had a nice tone, but weren't too loud. Same question for you also, is the inlet centered in the mufflers and is the outlet centered? Are you running 2.5 all the way?

They do sound exactly like you described. Even inside the cab going down the road, the sound isn't bad at all. The first couple inches off the ramhorns are 2 inch, then the rest of the pipe and mufflers are 2.5 inch. I will check the inlet/outlet on the mufflers tomorrow and let you know.

Ray

[DeadheadNM]

Jud - Just some food for thought. In an attempt to keep my as-yet-uninstalled dual exhaust appear as OEM-like as possible I added another set of 4x4 exhaust hangers to match those on the other side of the frame. Hope the location of the added front hanger doesn't interfere with much: we'll see. Pete

[72 Super]

Originally Posted by 72 Super

They do sound exactly like you described. Even inside the cab going down the road, the sound isn't bad at all. The first couple inches off the ramhorns are 2 inch, then the rest of the pipe and mufflers are 2.5 inch. I will check the inlet/outlet on the mufflers tomorrow and let you know.

Ray

Hey Jud,

My mufflers have center inlets and the outlets are to the outside closest to the frame on both sides.

Ray

[68_Shortbox]

Here are some pictures I took when we took the bed off of my '68 SWB 4x4. The mufflers are Flowmaster 40s. I didn't find the in cab noise to be bad but my dad said he could hear me coming home from a few blocks away.