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What kind of intake? Those cyls would be "fed together" on a dual-plane intake. I would be looking into something carb/intake-related.

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I was wondering that too so maybe dirt in the carb only one front side getting gas at idle!

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I have used water on the headers right at the exhaust ports and on the cylinders that is not running the headers are not hot enough to steam of the water from the spray bottle. I also find it strange that the plugs are not wet?
Yeah the engine only want to idle high and it runs bad, where and how should i look for the vacum leak?

the distributor is a mopar electronic with a Magnetic Pickup, Mechanical, Vacuum Advance (brown cap)

intake is edlbrook preformer rpm

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Two ways I know of to check for a vacuum leak with common tools.

1.) Use a propane torch (unlit) with a piece of rubber tube and run that propane around the intake/carb base (engine running) where you think it might be leaking. If there is a vacuum leak, it will pull in the propane gas and make the engine pick up rev's all the sudden.

2.) Basically do the same thing with carb/choke cleaner by spraying it around the same areas and seeing if the engine revs up.

I will warn you vacuum leaks can be tricky to track down with even these methods sometimes. Mechanics use a device that emits a smokey vapor and they use that to see where it is being sucked into the motor. However, these devices cost hundreds of dollars.

Try these tricks and see if you can't pinpoint it. If you have changed the intake recently, this is probably a vacuum leak. As others have said, it could a very dirty carb where it's not getting fuel at idle BUT that would be easy to test as the issue would disappear once you revved the motor up and got on to the primary circuit.

Cylinders being improperly fed the correct fuel mixture can cause different exhaust port temps. Contrary to popular belief, my experience is that cylinders running rich (or not getting good spark) will actually have very hot exhaust ports (headers glow) where lean conditions can do the opposite. The extra fuel from a rich cylinder actually is getting ignited right outside the cylinder in the exhaust port!

This sounds like a air/fuel issue to me. It is very unlikely your ignition would hit on 4 of 8 cylinders and do this consistently.

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How do you know it's only running on 4 cylinders? I don't see a V8 running at all with only 4 cylinders...maybe 6 at worst.

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A V8 certianly would only run a 4 , A friend did it with a 396 many , many years ago , he actually drove the car up a steep incline , commented on how bad it was running , open the hood and 4 wires on the right bank are laying on top of the air cleaner ... .

this looks like a carb problem , Carb cleaner and compressed air to clean out passages .

how old is the carb that is being used ?

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sounds interesting....could you please give me a crash course on cleaning the carb? where on the carb do I find the idle circet?

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Yes one of the idle circuits being clogged could cause this. I am no expert but I would think if you take out the idle adjustment screw on the side in question (drivers) and blow it out with compressed air/carb cleaner really well. Make sure you count how many turns it took to get the screw out.

A better way is to count the turns the bottom out the screw and then use that as a reference when you replace it after the cleaning.