1971 Exhaust Manifold swap
Printed From: TheAMCForum.com
Category: Competition
Forum Name: Jeeps and Eagle 4x4 fun.
Forum Description: Rock crawling events or results, Muddin' it through the riverbed with your Eagle
URL: https://theamcforum.com/forum/forum_posts.asp?TID=113837
Printed Date: Apr/24/2024 at 12:18am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: 1971 Exhaust Manifold swap
Posted By: RobinPDX
Subject: 1971 Exhaust Manifold swap
Date Posted: Jan/02/2022 at 9:38pm
 Found these manifolds (see pix) and am considering them and replacing my OEM manifolds. Anyone know If there is a fitment issue with the swap out? From what I can tell, it appears to be plenty room clearance on things, starter, frame, shifters etc. Any input or opinions on this is appreciated, thx. ------------- Rob Wiley |
Replies:
Posted By: Sonic Silver
Date Posted: Jan/02/2022 at 10:05pm
| Looks like Junkyard Dog's parts. Did his ad say no texts? |
Posted By: RobinPDX
Date Posted: Jan/02/2022 at 10:20pm
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Yes I think he did say something like that, Are you familiar with the person or have maybe already seen these pieces? Are they junk? ------------- Rob Wiley |
Posted By: Sonic Silver
Date Posted: Jan/03/2022 at 1:53pm
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RobinPDX wrote:Posted By: scott
Date Posted: Jan/03/2022 at 4:17pm
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Shop around, you will be able to find similar manifolds for less. They may have holes in them for the air injection tubes, but those are easy to plug. Run a "wanted" ad on this forum & see what turns up. As far as fitment, I'm not sure. I suspect if Jeep uses a different exhaust manifold they do it for a reason. ------------- "Prolly" is not a word. |
Posted By: mramc
Date Posted: Jan/03/2022 at 5:29pm
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I believe you can get new AMC cast iron type free flow exhaust manifold. Check on line. I pretty sure CROWN makes them , not sure if any one else does, but you can get them new. CAVEAT Crown is Chinese so quality may not be up to par. I just know new is available , probably Crown, most likely China. I've just seen them on line check the Jeep parts vendors on line. LRDaum ------------- LRDaum |
Posted By: RobinPDX
Date Posted: Jan/03/2022 at 7:02pm
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Yes checking around may be the ticket to locating some. I didn't expect any real gains to speak actually. Had considered some aftermarket headers also which might be just as good for my purpose. Crown might be fine as supreme quality isn't part of the plan here. So posting "wanted" might be the best next step.
------------- Rob Wiley |
Posted By: THE MENACE
Date Posted: Jan/03/2022 at 7:18pm
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PM Sent!! ------------- Former Owner of: The Craig Breedlove "AERO AMX" Still Owner: SS/AMX #9 replica (THE BIG MENACE) 70 AMX 416, EFI, Nash 5 speed 70 Javelin 401, 727 (Wife's car) 72 Gremlin Autocross Project. |
Posted By: 70,71,72 AMXS
Date Posted: Jan/04/2022 at 6:15am
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Guessing you have the front dif housing on the drivers side and the OEM manifold is the log style? I have put regular free flows on FSJ Jeeps like that, and any good exhaust guy can make it work. Unless you are doing some extreme off roading/ rock crawling, you shouldn't have any issues. I did a test on the last Wagoneer I did, and even at the stock ride height, I couldn't make the exhaust touch the dif housing jacking up the right rear and getting full compression on the left front suspension. Not sure what Jeep was worried about on these... ------------- Bruce in NW Ohio |
Posted By: BlackOpsOutdoors
Date Posted: Jan/04/2022 at 2:17pm
| Do these flow similarly to a header? They sure look like it. |
Posted By: RobinPDX
Date Posted: Jan/04/2022 at 3:31pm
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I do not plan on any rough terrain driving, Maybe a little but not much. The thing was meant to be my HomeDepot currier rig, yet it's a guy thing and of Course I cannot seem to leave it well enough alone.. Now if only I can reel in my imagination about "what next" can I do to it...Guy stuff ...
------------- Rob Wiley |
Posted By: mramc
Date Posted: Jan/05/2022 at 12:38pm
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Do these flow similarly to a header? They sure look like it. Yes, They are some times referred to as cast iron free flow headers. LRDaum ------------- LRDaum |
Posted By: Sonic Silver
Date Posted: Jan/06/2022 at 11:14am
| On my modified 360, the free flow exhaust manifolds were down 21 horsepower and 32 ft/lbs torque to a set of 1-3/4 inch headers on an engine dyno. On a stock engine, I would think the difference would be less. |
Posted By: RobinPDX
Date Posted: Jan/06/2022 at 11:17am
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I considered he possibilities of headers or the better OEM cast Iron pieces. It's almost a default headers win all around in performance. So, If I cannot locate the Early OEM cast iron ones with Air injectors holes, I will likely go headers. ------------- Rob Wiley |
Posted By: Sonic Silver
Date Posted: Jan/06/2022 at 11:37am
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Posted By: 70,71,72 AMXS
Date Posted: Jan/07/2022 at 6:19am
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I ran headers on my J10 for many years with no issues. Made sure they actually lined up fairly well with the mounting surfaces and used the copper infused RTV on both sides of the gaskets. Retorqued them several times during the first month, and didn't touch them again. Now my FSJ Cherokee with a 401 and used for plowing snow, was a different story. couldn't keep gaskets in that, had to go back to free flows.. ------------- Bruce in NW Ohio |
Posted By: mramc
Date Posted: Jan/07/2022 at 5:09pm
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You buy new AMC V-8 cast iron free flow manifold from Omix-ADA BUT , and it is a big BUT they are probably more costly then headers. On the other hand you can change a starter with removing a header with the cast iron manifolds. The Jeep vendors sell Omix-ADA parts (Taiwan Made) and prices may vary. LRDaum ------------- LRDaum |