Dougs D103 headers
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=100961
Printed Date: Apr/19/2024 at 12:06pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: Dougs D103 headers
Posted By: Purpleheart
Subject: Dougs D103 headers
Date Posted: Jul/12/2019 at 2:52am
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I'm considering putting a set of Dougs D103 headers on my 72 Javelin AMX . It's a 401 with a 904 automatic transmission . I'd like to hear how they fit from people that have installed them in 71 - 74 Javelins . Do they fit without hammering or denting them and how's the ground clearance ? ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Replies:
Posted By: Purpleheart
Date Posted: Jul/14/2019 at 10:28pm
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I guess I'll just take my chances and order a set . I was really hoping to get some feedback from someone that's put a set of these on a 71 - 74 Javelin . ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Posted By: 343sharpstick
Date Posted: Jul/15/2019 at 10:14am
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I have the D103's on my '69 Javelin with a 5-Speed T5. I did need to do some work on the flanges to work with my Edelbrock heads and trim the motor mount on the passenger side. There is info elsewhere on the forum on that. I would recommend getting a set of headers in bare steel and modify as needed. http://theamcforum.com/forum/dougs-headers-pictures_topic40234_page6.html" rel="nofollow - http://theamcforum.com/forum/dougs-headers-pictures_topic40234_page6.html |
Posted By: Purpleheart
Date Posted: Jul/15/2019 at 2:36pm
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Thanks , I'll modify the right bracket for clearance ! ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Posted By: brownspirit
Date Posted: Jul/15/2019 at 5:16pm
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I haven’t seen him around lately, but I believe AMXTRA has a set on his humpster. Andy
------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: Purpleheart
Date Posted: Aug/10/2019 at 12:15pm
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The Doug's D103 headers have been delivered and they are the worst headers I've ever bought . They won't even bolt on because there's weld in one of the bolt holes and weld spatter that wasn't cleaned off before they put the ceramic coating on . The ports don't match up worth a crap . There's a bunch of spatter in the flange opening and in the tubes . I'll have to break out the die grinder just to get the headers to bolt on . It has the removeable pipe on the back passenger side that looks like it's gonna have an exhaust leak there . Has anyone had to weld the removeable pipe ? Don't buy these headers , they are junk . ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Posted By: scott
Date Posted: Aug/10/2019 at 1:27pm
| Have you considered these headers? They get great reviews. https://americanracingheaders.com/collections/amc/products/amc-amx-headers" rel="nofollow - https://americanracingheaders.com/collections/amc/products/amc-amx-headers |
Posted By: AMXFSTBK390
Date Posted: Aug/10/2019 at 2:44pm
Scott, I went to the above website you posted. They list AMC headers by: small body/large body/Ambassador. How is an AMC owner to know what body size their car is? For instance is a 71 Javelin or a 69 Rebel a small body car or big body car? What size is a 68-70 AMX ? ------------- Questions are powerful tools...what's in your toolbox? |
scott wrote:Posted By: Purpleheart
Date Posted: Aug/10/2019 at 3:50pm
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On the right side header there's so much extra weld in one of the center bolt holes that I have to use my die grinder to put it on because I can't even get a 3/8 thread bolt through the hole ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Posted By: WesternRed
Date Posted: Aug/10/2019 at 4:26pm
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Small body is American, Hornet, Gremlin etc, large car is all the bigger cars including Javelin and AMX. ------------- I've finally given up drinking for good...........now I only drink for evil. |
Posted By: tufcj
Date Posted: Aug/10/2019 at 4:28pm
Small body is American, Gremlin, Hornet, Concord, Spirit, etc. Large body are the AMX, Jav (all years), Rebel. Bob tufcj ------------- 69 AMX 74 Javelin AMX 67 Rogue If you need a tool and don't buy it... you'll eventually pay for it... and not have it. Henry Ford |
Posted By: AMXFSTBK390
Date Posted: Aug/10/2019 at 5:55pm
Having a problem following that logic because: a 1970-71 Hornet SC/360 has a wb 108" bdy lgth 184.9" a 1968-70 AMC AMX /290 has a wb 97" bdy lgth 177.2" ....yet you posted the Hornet is a small body car when it's dimensions are larger than a 1968-69 AMX. Back in the day cars were categorized as: subcompact, compact, mid-size, full size, sports car. I wonder what American Racing Headers would say. They don't say on their website. I would want to know because there is a chance someday I'd buy their headers. ------------- Questions are powerful tools...what's in your toolbox? |
Posted By: tufcj
Date Posted: Aug/10/2019 at 6:41pm
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What ARH is going by is the width of the engine compartment. The engine compartment is much narrower on the "small body" cars listed above. If you try to use AMX headers in a Hornet, they're much too wide to fit. The "small body" headers tuck much closer to the engine. Bob tufcj ------------- 69 AMX 74 Javelin AMX 67 Rogue If you need a tool and don't buy it... you'll eventually pay for it... and not have it. Henry Ford |
Posted By: AMXFSTBK390
Date Posted: Aug/10/2019 at 7:21pm
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Very interesting. Thank you for the logical explanation. ------------- Questions are powerful tools...what's in your toolbox? |
Posted By: 68-73 amx
Date Posted: Aug/10/2019 at 10:06pm
| If things like port matching are important to your build , ARH match up perfectly to your heads , no work needed there. Same with fit and finish , The header bolts go in with no problems, you can get a spark plug socket past the flange because its CNC to give you room. The flanges are thick enough not to warp and leak. They fit your car . If you want to lift your engine and trans out together you could put one strap on one tube on each side of these headers and lift them out together (don't try but they are that strong ). I have a pair and they are great. |
Posted By: 343sharpstick
Date Posted: Aug/12/2019 at 8:52am
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If you want to save some cash on an "affordable" header the D103's are OK but do a couple hours of work with the die-grinder, and I did weld on a new flange. I guess my expectations are low when it comes to just about anything for my cars. If something fits without needing some modification I'm usually shocked. When I purchased the Dougs headers, it was the only off-the-shelf header available at that time that had decent ground clearance. The new headers that are available are better, but more expensive.
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Posted By: Steve_P
Date Posted: Aug/12/2019 at 9:32am
This. The small body cars are at least an inch narrower between the frame rails. |
Posted By: Red Devil
Date Posted: Aug/12/2019 at 10:02am
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... but any reason why a "small body" header won't fit a "big body" car? I've had Hedman's on both. My understanding is the ARH "big body" headers don't clear a wider-than-stock sump oil pan, but the "small body" headers actually have more pan clearance. Not sure if anyone with a "big body" car e.g. Javelin or AMX is running the ARH "small body" headers ... specifically, if they also have an Aviaid or Armando pan and does it clear? 'Guess a better subject for another thread. Thanks,RD
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Posted By: 343sharpstick
Date Posted: Aug/12/2019 at 10:31am
I have a custom oil pan with with wide base etc, and the Dougs D103's fit nicely in that area. I'll share this old crappy pic. They weren't perfect, which is why I recommend getting them in bare steel, and updating them a bit. With some work mine are functioning nicely, and I can get them out of the bottom of the car when I need to remove them. You can see how the pan, and headers fit nicely up at the front of the car. The Pan sits .25 inches lower than the stock engine cross-member and level with the bottom of the bell-housing. The headers are maybe .5 inch lower than that. Hope this helps everyone decide what to buy. No easy answer.  |
Posted By: Ken_Parkman
Date Posted: Aug/12/2019 at 11:05am
| The small body engine support brackets are different than the big body, and some small body headers running close to the block interfere with the bracket on the right side. I have successfully used a 7105 Hooker on a Javelin by cutting a chunk out of the bracket. |
Posted By: Purpleheart
Date Posted: Aug/18/2019 at 1:13am
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I got them in my 72 Javelin/AMX now . The driver side went in really easy . The passenger side took some work modifying the engine mount bracket . I cut a chunk out of it and welded it back together . I also had to rotate the motor mount 180 degrees . It bolted right in after that . Even through they're in now , I wouldn't recommend them . Next time I'll just bite the bullet and buy the American Racing Headers for double the price . ------------- Best time 10.38, Best mph 128.73, Best 60ft 1.38 |
Posted By: badamx
Date Posted: Nov/20/2019 at 5:51am
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I am currently running port matched free flows on my '70 390 AMX. The AR headers although spendy are tempting. Might be an obvious answer, but will going to the header give me a significant bump in the seat dyno? Also can I get a recommendation on a company to do a ceramic coating should I chose to get them? ------------- badamx/Doug Bader 1970 AMX 390 4 Speed Frost White/ Red Leather 1970 Schwinn Apple Krate |
Posted By: BassBoat
Date Posted: Nov/20/2019 at 7:30am
| Yes. On log manifold cars, the bump is probably a half a second in quarter mile ET. Your free flows are a little better so you won't get quite the bump, but you will feel it. Since you asked, I assume you haven't run headers before, so I would point out that they will be noisier. Also, a very restrictive exhaust with stock style mufflers won't get quite the maximum benefit out of the headers. Have fun! |
Posted By: Heavy 488
Date Posted: Nov/20/2019 at 7:35am
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No telling your location, but Google it. Maybe someone in your area doing it. I had headers and associated pipes coated a little more than 2 years ago. |