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Old 02-24-2021, 08:24 AM   #1
Acregger
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Exhaust/Mufflers

Hey guys getting about time for exhaust for my 71 k10 with a 5.3, just trying to see what you guys went with. I have had very good luck and like the sound of Magnaflows in the past but torn between 14 inch and 18 inch. I dont want it terribly loud but sound good. It little hard to listen to the sound on you tube as all the Silverado's on there have cats. Seeing your thoughts and maybe a sound clip.

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Old 02-24-2021, 09:35 AM   #2
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Re: Exhaust/Mufflers

I'm in a similar position. At this point, I'm looking at using a single Magnaflow Delta 50 or Delta 70 muffler. I don't mind a little rumble, but I don't want it to be loud at all. I will be installing cats on mine. I don't know yet whether I'll install a resonator or not.
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Old 02-24-2021, 10:11 AM   #3
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Re: Exhaust/Mufflers

I bought the Hooker Blackheart set up. Fit great, but it does need the holes cut in the trailering arm cross member.
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Old 02-24-2021, 10:51 AM   #4
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Re: Exhaust/Mufflers

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Originally Posted by 1971Stepside View Post
I bought the Hooker Blackheart set up. Fit great, but it does need the holes cut in the trailering arm cross member.
What kind of modifications to hook to a 4x4 truck and the LS?

Last edited by Acregger; 02-24-2021 at 11:02 AM.
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Old 02-24-2021, 11:04 AM   #5
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Re: Exhaust/Mufflers

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What kind of modifications to hook to the truck and the LS?
None, if you have the holes already cut in that crossmember. The kit is designed to sit inside the frame rails and not hang down under the frame. You will also have to work out making the connection to your headers/manifolds to the pipe since they all differ, but that is pretty simple to do. You can look at the Blackheart thread in this LSx Swaps section or look at my build thread (1971 Stepside LS Build) to see more pics.
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"I can't complain, but sometimes I still do. Life's been good to me so far."
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Old 02-24-2021, 11:18 AM   #6
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Re: Exhaust/Mufflers

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Originally Posted by 1971Stepside View Post
None, if you have the holes already cut in that crossmember. The kit is designed to sit inside the frame rails and not hang down under the frame. You will also have to work out making the connection to your headers/manifolds to the pipe since they all differ, but that is pretty simple to do. You can look at the Blackheart thread in this LSx Swaps section or look at my build thread (1971 Stepside LS Build) to see more pics.
Cool, I looked at the website under my truck and LS swap but didnt show a kit
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Old 02-24-2021, 12:56 PM   #7
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Re: Exhaust/Mufflers

https://67-72chevytrucks.com/vboard/...d.php?t=790866
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"I can't complain, but sometimes I still do. Life's been good to me so far."
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Old 02-24-2021, 11:12 PM   #8
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Re: Exhaust/Mufflers

The 2wd Hooker Blackheart LS exhaust is not going to work on a 4 x 4 without modification
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Old 02-25-2021, 10:15 AM   #9
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Re: Exhaust/Mufflers

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The 2wd Hooker Blackheart LS exhaust is not going to work on a 4 x 4 without modification
Great point! I missed the "K" in 10. Thanks Captainfab
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1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021.

"I can't complain, but sometimes I still do. Life's been good to me so far."
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Old 02-25-2021, 12:38 PM   #10
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Re: Exhaust/Mufflers

I have flowmaster 40 series on my 5.7 and its too loud. Wasn't a big deal as a kid but it is as an adult.
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Old 02-25-2021, 04:18 PM   #11
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Re: Exhaust/Mufflers

I went with Magnaflow XL 3 chamber mufflers. I wanted something not too loud. At first I just had turn downs behind the mufflers and there was a lot of drone. Tailpipes to the back helped that. Not quiet by any means but tasteful and of course louder when you tromp on it. If anything it has too much "slap" when I step on it. May try some resonators. I have shorty headers.

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Old 02-25-2021, 08:05 PM   #12
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Re: Exhaust/Mufflers

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Originally Posted by bigmoe View Post
I went with Magnaflow XL 3 chamber mufflers. I wanted something not too loud. At first I just had turn downs behind the mufflers and there was a lot of drone. Tailpipes to the back helped that. Not quiet by any means but tasteful and of course louder when you tromp on it. I have shorty headers.
Can you explain what you mean by drone? I've been hearing the term for some time, but haven't been sure. Is it simply exhaust note in the cab, or is it something worse?

Reason I ask, I'm building the truck in my signature, and I WANT to clearly hear the engine in the cab, but I want it as quiet as possible outside the truck. It's fun to have a deep exhaust note when rowing the gears, but I don't want the neighbors to say, "There he goes again..."

I know this truck will have less insulation on the firewall than the donor Tahoe did. I don't know how much I'll hear the engine itself through the firewall, without needing to add the exhaust note to it as well.

I've driven two trucks extensively that had a single glasspack and a turn down exhaust underneath the bed. One was a 1973 f100 with a 360fe, and the other is a 1981 f150 with a 300i6. I'm currently driving the second one. I've really enjoyed the exhaust note of both, and feel it's about perfect, aside from the crackling on deceleration. I've been really surprised how quiet each truck has been, which doesn't make sense with the glasspacks.
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Old 02-25-2021, 11:03 PM   #13
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Re: Exhaust/Mufflers

Drone is at lower rpm. It's a loud and echoey hummmm. Lol I'm trying to figure out the best way to explain. Maybe try youtube exhaust drone.

Last edited by bigmoe; 02-26-2021 at 11:39 AM.
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Old 02-26-2021, 08:25 AM   #14
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Re: Exhaust/Mufflers

I am in the same spot, dont want the drone. I like to hear it and it have a good sound but not terribly loud. I think I may just have a guy do custom exhaust and hope for the best.
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Old 02-26-2021, 09:49 AM   #15
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Re: Exhaust/Mufflers

Whatís quieter flomaster 50s magnaflow 70s ?
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Old 02-26-2021, 10:02 AM   #16
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Re: Exhaust/Mufflers

Borla mufflers can be expensive but I have used them and recently installed one on my newer truck. They have a nice rumble on startup and idle but seem to calm down when driving. They will roar when you get on them.
I had this on my 68 but with the turbo and resonator it was quiet. I am trying something different on it, the turbo changes it significantly.
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Old 03-05-2021, 09:29 AM   #17
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Re: Exhaust/Mufflers

Had exhaust put on my truck yesterday went with the flow master 50s not impressed much louder than I expected from what I had heard but what I dislike the most is when you rev it up it has a crackle when you let off Sounds like sh t
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Old 03-07-2021, 09:44 AM   #18
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Re: Exhaust/Mufflers

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Had exhaust put on my truck yesterday went with the flow master 50s not impressed much louder than I expected from what I had heard but what I dislike the most is when you rev it up it has a crackle when you let off Sounds like sh t
That worries me too, I dont like that crackle either.
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Old 03-16-2021, 01:37 PM   #19
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Re: Exhaust/Mufflers

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Originally Posted by nsb29 View Post
Had exhaust put on my truck yesterday went with the flow master 50s not impressed much louder than I expected from what I had heard but what I dislike the most is when you rev it up it has a crackle when you let off Sounds like sh t
Funny you mention the crackle. I just had my exhaust done due to the LS swap and now I have the crackle. I never had it before when i had the SB 350 and I am using the same Magnaflow mufflers I used then. Three differences between the old and new exhausts- the old system had an "X" pipe installed where as now it is just true duals and also the mufflers are further towards the rear of the truck than before and lastly I am running mid-length headers now and had long tube headers before. My system is actually quieter than before but when you get in the gas it sounds like crap. Is your exhaust a true dual setup?
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Old 03-16-2021, 06:03 PM   #20
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Re: Exhaust/Mufflers

I have the cast manifold that came with the motor which is from a Pontiac G8 I believe similar to the Camaro cast manifolds from there is 2 1/2 inch exhaust back to the mufflers and then exit behind the rear wheels I did not use an H Or X pipe driving down the highway it really isnít that loud but going through the gears itís louder than I wanted I am considering installing two small glass packs behind the mufflers in a straight area about a foot and a half from the end I also wondered if it was because I did not install an H or X pipe ????? I also wondered if it was the brand I bought and maybe I should have bought magnaflows but if youíre having the same problem thatís obviously not it if you figure out something before I do post it Iíll do the same
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Old 03-17-2021, 07:27 AM   #21
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Cool Re: Exhaust/Mufflers

cackle is partially caused by decel timing and fuel settings in pcm file. a tuner can adjust that out.
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Old 03-17-2021, 08:14 AM   #22
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Re: Exhaust/Mufflers

Thanks for that information my plan has been once the truck is 100% done taking it to a tuner I think I may still add the glass packs just to help mellow it out some
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Old 03-17-2021, 03:16 PM   #23
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Re: Exhaust/Mufflers

Some people add resonators in the section before the mufflers. You can get some after market resonators that are about 12" long and fairly small in diameter. Great for reducing drone too. Summit has Vibrant brand which are reasonably priced.
Edit: From what I've been looking at for resonators most are basically glass packs in various lengths. I think I might try some glass packs before the muffler to reduce the "slap" wet fart sound when tromped or revved up.

Last edited by bigmoe; 03-24-2021 at 08:06 PM.
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Old 03-17-2021, 05:39 PM   #24
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Re: Exhaust/Mufflers

Never used them I thought they went after Iíll look into it
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Old 03-17-2021, 10:48 PM   #25
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Re: Exhaust/Mufflers

GM 3800 v6 cars have resonators between the cats and the muffler. Removing them creates a terrible rasp and fart noise at idle. They are essentially a perforated glass pack design thats straight through.
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