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Engine cradle/crossmember

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=100464
Printed Date: Mar/28/2024 at 1:12pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com


Topic: Engine cradle/crossmember
Posted By: Amc wannabe
Subject: Engine cradle/crossmember
Date Posted: Jun/10/2019 at 8:49pm
i have a quick question for the gurus and “make it work”era on here.

I have received mixed advice as to what year javelins crossmembers work for the 1970 javelin. Some have said it’s a one year only, some say first gen, some say second due to the matching suspension style. I just want to buy once and cry once, but all this mixed information has got me thinking I will get burnt wether I like it or not. 

Anybody have hands on experience that can weigh in? Ever try to cross generations on these with luck? I just want to fit my 80s 360 into my 1970 with only the normal headaches haha



Replies:
Posted By: PHAT69AMX
Date Posted: Jun/10/2019 at 8:58pm
This from the 67-72 Parts Manual may help, but is absent the '73-4 info...
Maybe some one can post the '73-74 Parts Manual info...



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Link to a http://www.youtube.com/watch?v=MySiKQsmWxU" rel="nofollow - Short YouTube Burnout Video



Posted By: Trader
Date Posted: Jun/10/2019 at 9:21pm
If you have a 6 cylinder cross member in it now you can buy these:
http://www.bulltear.com/catalog/product_info.php?products_id=275" rel="nofollow - http://www.bulltear.com/catalog/product_info.php?products_id=275
Expensive but will work.
All other year cross members will require modifications as far as I know.
Good luck in the hunt!



Posted By: AMXFSTBK390
Date Posted: Jun/10/2019 at 9:23pm
If I had to hazard a guess as to what AMC V8 engine crossmembers are interchangeable it would be 1968-1974 AMX/ Javelin.

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Questions are powerful tools...what's in your toolbox?


Posted By: purple72Gremlin
Date Posted: Jun/10/2019 at 9:43pm
Originally posted by Trader Trader wrote:

If you have a 6 cylinder cross member in it now you can buy these:
http://www.bulltear.com/catalog/product_info.php?products_id=275" rel="nofollow - http://www.bulltear.com/catalog/product_info.php?products_id=275
Expensive but will work.
All other year cross members will require modifications as far as I know.
Good luck in the hunt!

not for Javelins or AMXs.  Only small cars. Meaning Americans, Hornets Gremlins, Concords, and spirits. And they will not work on the 4 cyl CM either


Posted By: PHAT69AMX
Date Posted: Jun/10/2019 at 10:32pm
1969 & 70 Rebel (10) V8 and 1968-69-70 AMX & Javelin (30-70) V8 all use
318 9238 Front Crossmember per the above 67-72 Parts Manual page
but I am not sure why they both also say "(Ref Pr. List)"...

321 8703 it says is for 1971-72 Matador & Javelin V8, but hand written in and
321 1129 being crossed out...

Which I guess implies the '71 & up Javelin Front Crossmember is different ?
? Most likely due to Suspension Change ?  Is that how you all read it ?


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Link to a http://www.youtube.com/watch?v=MySiKQsmWxU" rel="nofollow - Short YouTube Burnout Video



Posted By: Buzzman72
Date Posted: Jun/11/2019 at 6:02am
"Ref Pr. List" usually meant that there was a supercession that wasn't yet in the parts book.
 
Since the suspension changed for the 1970 model year, apparently the LCA mount didn't on the Javelin.
 
With the '71-up Javelin being the 'humpsters," something may have changed where the crossmember meets the front unibody frame.


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Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.


Posted By: WesternRed
Date Posted: Jun/11/2019 at 6:11am
I would have thought all 68 onward V8 large car (including Javelin) cross members interchange except for the Ambassador.

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I've finally given up drinking for good...........now I only drink for evil.


Posted By: Amc wannabe
Date Posted: Jun/11/2019 at 6:12am
yeah, I’m more confused than before haha. I was hoping a few guys did a swap in the past, sounds like the most we have to go on is the parts numbers?


Posted By: farna
Date Posted: Jun/11/2019 at 6:30am
The front crossmembers for Javelin and AMX models interchange from 68-74. The lower suspension arm didn't change, just the upper arm when the upper trunnion was replaced with a ball joint (lower trunnions were last used in the 63 American, replaced with a ball joint in 64... 62 in big cars). The bodies are all the same width. The Rebels and Matador use the same crossmember, and according to the parts book fits the Javelin also. According to the 71 TSM there is 1/64" difference in front sill outside to outside width between the Javelin and Matador, with the big car being 1/64" wider (35-7/32" vs 35-14/64").

Changes in part numbers don't necessarily mean anything... or maybe I should say everything! Numbers changed due to a different supplier or minor change... different grade or thickness of metal, a bolt hole moved/added/deleted, etc. On one or two occasions part numbers changed because the numbers were getting convoluted and AMC decided to streamline them, though I can't remember exactly when that was and if it affected all numbers or just specific groups. Sometimes they changed because the supplier changed part numbers for some reason, but there is practically no difference in the part. Part numbers are a good place to start, but more investigation is needed. 


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Frank Swygert


Posted By: Steve_P
Date Posted: Jun/11/2019 at 7:13am
The fastener layout changed on the later Javelin crossmembers. They will interchange if you use the correct fasteners. The second gen crossmember only uses countersink style fasteners on one side of the car vs both sides for the first gen.

The lower control arm did change in 1970 but the mounting into the crossmember is the same.

AMC set the part numbers, not the suppliers.


Posted By: FritzF3
Date Posted: Jun/11/2019 at 7:23am
14/64 is the same as 7/32. Did you mean 15/64?
Fritz


Posted By: Amc wannabe
Date Posted: Jun/11/2019 at 1:31pm
Steve, when does that change occur? Would my 1970 straight six fall into the early or late category?


Posted By: 401MATCOUPE
Date Posted: Jun/11/2019 at 2:36pm
The attachment fastener change happened in 1971.....

68-70 uses 2 bolts with a taper under the head, the same bolts used to hold many tractor wheels in place and 2 studs with lugnuts...taper side towards crossmember.

71 up used the two studs with lugnuts and 2 each 1/2"- 20 bolts with thick flat washer under head.

All 68=70 V-8 Javelin and AMX Crossmembers will interchange with no issues on control arms or engine mounting.

If you need one PM me I have several used from Javelin.


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Ross K. Peterson
68X,GoPac,343,AT,52A(1stCar)
68X,GoPac,390,4sp,52A
69X,GoPac,390,4sp,64A
70X,GoPac,390,4sp,87A,8
70X,GoPac,390,4sp,BBO,8
70 Jav SST,390,AT,BSO
74MatX,401,AT,Prototype
74MatX,401,AT


Posted By: farna
Date Posted: Jun/12/2019 at 6:59am
Yes Fitz... meant 15/64!!

AMC set the part numbers, but they usually changed part numbers when they changed vendors on many parts, or when vendors made a change so they could tell where the part came from in case of issues later.


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Frank Swygert


Posted By: Amc wannabe
Date Posted: Jun/13/2019 at 7:02am
401matcoupe, I sent you a message. Looks like your relatively close to me? Might be able to snag it in the coming weeks if your free and not wanting it’s weight in gold haha


Posted By: 401MATCOUPE
Date Posted: Jun/13/2019 at 7:07pm
Originally posted by Amc wannabe Amc wannabe wrote:

401matcoupe, I sent you a message. Looks like your relatively close to me? Might be able to snag it in the coming weeks if your free and not wanting it’s weight in gold haha

Plenty of parts here after parting out 100's of AMC's!!  Prices are always reasonable, sent you PM and my number.


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Ross K. Peterson
68X,GoPac,343,AT,52A(1stCar)
68X,GoPac,390,4sp,52A
69X,GoPac,390,4sp,64A
70X,GoPac,390,4sp,87A,8
70X,GoPac,390,4sp,BBO,8
70 Jav SST,390,AT,BSO
74MatX,401,AT,Prototype
74MatX,401,AT



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