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post #1 of (permalink) Old 10-02-2000, 03:04 PM Thread Starter
 
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4.0/258 question

I finally located a 4.0 head and exhaust manifold from a 92 cherokee for my 258. Many thanks to all for all the help and the great links, especially www.monsterslayer.com/jeep/40Head/40Head.htm!
My plans are to run this combo with the 4.2 intake manifold, since I am quite content with my Weber 38.
However, because the old intake manifold sits higher on the 4.0 head, it appears alot of the cupped washers will "miss" intake manifold and not secure it to the head.
Has anyone else run into this and what is the solution?
Any help/tips/links will be GREATLY appreciated, I want to get this problem solved before I send the head to the machine shop.
TIA,
Bob in MA

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post #2 of (permalink) Old 10-02-2000, 04:58 PM
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Re: 4.0/258 question

Sorry to get you excited if you thought that I had the answer, 'cause I don't. I just am very interested in this swap and was hoping you could let me know how you resolve this problem. I have the same carb and was hoping to use it in the same swap. [email protected]

84 CJ-7/258,Weber 38,Jacob's Omni Mag,flowmaster,3.5" SL,32" BFGMT, Superior 1 peas
post #3 of (permalink) Old 10-02-2000, 05:09 PM
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Re: 4.0/258 question

you are going to run the Weber instead of the EFI? Something there dont sound right.

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post #4 of (permalink) Old 10-02-2000, 05:28 PM Thread Starter
 
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Re: 4.0/258 question

Well, I have had my Weber for about 10 years and it runs great, I see no need to replace it, considering the cost. It runs just as well on bouncy stuff/inclines/sidehills as my friends rig who does have the MPI kit. We have some pretty good rocks out here on this side of the state! Have you been to Sylvester Road near Northampton? Check out this pic, and my carb ran fine..

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post #5 of (permalink) Old 10-02-2000, 09:35 PM
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Re: 4.0/258 question

Back some time ago, we had a discussion on this issue. To recap options: 1) go to hardware store and pick up larger washers, 2) go to a speciality store and pickup larger and hardened washers, 3) have larger, squarer washers made by the machinist (if you do it right you will then need to grind them down to fit, since the thickness of the 258 intake and 4.0 exhaust are slightly different and the spacing between the intake and exhaust are more. I used 3/8" steel. Good Luck.

Mindbender 85CJ7 I258 [img]/wwwthreads_images/icons/smile.gif[/img] 40 head ported polished [img]/wwwthreads_images/icons/smile.gif[/img]
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post #6 of (permalink) Old 10-03-2000, 09:52 AM
 
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Re: 4.0/258 question

Bob-
The cupped washers for a 4.0 are reportely larger than the 4.2 variety.
This would me the ideal solution.
Let me know if it works, will ya?
I remember Cindy Allen having this problem.
She reported that she finally got hers working after recieving the larger 4.0 washer info but she never confirmed that these did the trick.

Tip: Place a 4.0 intake gasket onto the flange of your 4.2 intake.
You might see that the shapes are dissimilar and you might consider doing a little "matched port" work on the manifold.

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post #7 of (permalink) Old 10-03-2000, 06:19 PM Thread Starter
 
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Re: 4.0/258 question

It seems the commen answer is to use a variety of washer and stack them as need in order to retain the intake to the head. Ugly, but effective. I'll also look at the 4.0 cupped washers; my wife's Cherokke has a 4.0, but casual inspection didn't reveal any difference in them.
Sometimes I can't see the forest for the trees! I think it's because I am an aircraft mechanic by trade, and I can't help but apply those maintenance standards to my Jeep. Sometimes I have to remind myself when I start "overengineering' that Jeeps don't fly! (mostly)
Bob in MA

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