1978 Jeep 401 carb swap?

[Rodney]

I am really glad I found you guys!!!

I have a 1978 Jeep Cherokee with the original 401V8, auto trans, QT and so on and so forth. I want to dump the original MotorCraft 4 barrel carb and replace it with something that is as "bolt-on" as possible. I need a spread bore I guess, but cannot find one from Holley or Edelbrock any longer.

So, I am asking you guys who may have gone through this to recommend a carb swap for me that would require the least amount of effort. What works and why? How do I select the best carb for this purpose? Surely someone here has gone through this lately.

Thanks in advance. I am amazed at how stumped the people at all the parts stores and even the guys at Holley and Edelbrock have no idea what to recommend for this application!

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[JeepFreak]

Been there done that! I have tried and tried to find a carb that will fit this intake and have had no luck! What I and others have done is to retain the factory adapter plate(the plastic one) and use a spead bore adapter plate with that. Then you can use whatever carb you want. Being a 78 you have a two peice adapter plate so you will need to take of the seal plate that sits on top of the adapter. Then you are left with the plastic plate with each ear sticking up a 1/4 inch. You will need to machine these corners down untill the corners are flat with the plate. I used a hack saw on one of mine and it worked just fine. The other option is to get a 1/4 inch piece of aluminum stock and use the plastic adapter plate as a template. Just cut it out and you have an adapter plate. The problem with this AMC intake is that the bores going into the intake are raised. This is why it is so hard to find a carb to match. Once you make this plate just use the universal spread bore adapter(every parts store carries this) and bolt on carb of choice. If you have anymore questions let me know. I have used a Q-jet and several Holleys on mine with no problems. You will more than likely need to get new longer carb studs for this to work. Don't worry, it wont hit the hood! I retained my factory air breather with no problems.

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JeepFreak

[This message has been edited by JeepFreak (edited December 15, 2000).]

[Rodney]

Looks like that is what I will have to do. It has been recommened that I use the Edelbrock 1400 with their #2199 transdapt spacer. (Unless somebody tells me the Holley is much better.) I assume that I would still have to use the plastic spacer that came stock in conjunction with this if I understand you correctly. But I would no longer use the thick fiber spacer that came on it (or with any of the carb rebuild kits.)

Will I stand to lose a lot of performance from this type set up and should I use a gasket between the plastic spacer and intake or just go plastic to intake?

Thanks again for this really great site that helps all us full sized jeep owners out!

[JeepFreak]

I didn't seem to lose any torque. You only need to plastic plate to seal the manifold so after the plate you can run whatever spacer you like. Keep in mind the bolt patern for the intake. The 1400 series Edlebrock has a different pattern. Just get the right plates and you will be good to go. I personally think that torque is better with the stock intake versus the Performer intake. I have both on 360's and if some low end grunt is what your after i would stick it out with the stock 4V.

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JeepFreak

[JeepFreak]

Also you might search this forum for posts by Dean. He has the same setup that we have and he posted some good info as well.

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JeepFreak

[Rodney]

Well I'm getting closer all the time thanks to you guys.

I have two last problems - the first regards the fuel inlet which on most jeeps is on the drivers side. On the Edelbrock the fuel inlet is on the passenger side so I would have to fabricate new fuel lines to run on that side. Or can the Edelbrock's be moved over? I notice the casting has inlets on both sides but appears to only be bored and threaded on the passenget side.

Next up is the choke. The stock carb is a hot air choke. The Edelbrocks come with either an electric or manual. I'd go with the electric if all I need do is just rig up a "hot" wire to the choke connection. But I wonder if electric chokes operate through a sensor which the Jeep does not have in which case the electric choke is not much good. In that case I'd get the manual choke model. What gives here?

Man will I be glad once I can at least select the proper model carb! Thanks again.

[JeepFreak]

The electric choke is just grounded and wired to a hot. Pretty simple. The fuel inlet doesnt need to be moved. I fabed a braided fuel line to reach over there for mine. Problem is that I do not think that series carb will bolt up to the stock intake.

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JeepFreak