Vibrations.

[Hibbing_Coronet_500]

I replaced the intake manifold gaskets and valley pan too just last week. I put my single plane Tarantula back on. The car ran better with the Tarantula. I had the stock cast iron dual plane on there last summer and it wasn't as good.

[ws27]

Try pulling plug wires while the RPM is in the skipping/vibration range?

[Hibbing_Coronet_500]

I've done that. Only hole that doesn't change is cylinder #5. Wire tests good. Tried several plugs, compression is on par with others.

[Hibbing_Coronet_500]

I'm thinking cam or bent pushrod. Strangely it doesn't backfire

[ws27]

How did you test the wire?

Try swapping wire and plug with another cylinder just to make sure.

After that, you are looking at an internal problem. What about the dist cap?

[Hibbing_Coronet_500]

I've swapped and replaced 9 ways to Sunday. 3rd cap too. I do have some lifter noise, but I've heard worse on better running engines.

[67440Dodge]

Yes, torque converter can only bolt up one way.

I'd pull the valve cover on that side and then pull the coil wire and crank the motor over. Watch the rockers and make sure they depress the valve the same amount. If one doesn't, then you know you got a wiped cam lobe.

The strange thing is changing the intake seemed to make it less of a problem. This would make me lean towards a fuel system/vacuum leak. But pulling #5 and the problem doesn't change makes me lean towards a ignition/cylinder issue.

[Hibbing_Coronet_500]

I'm going to pull valve cover. Put a dial on them rockers. Not a fun job! They way I have them bolted down makes it a pain. The valve covers that is....

[Hibbing_Coronet_500]

Last night I brought home my vibration measuring equipment from work. I wanted to make sure I'm dealing with a bad cam.
My thoughts: If I had a misfire due to cam lobe wear? I would see that vibration at 1/4 engine rpm? Right?
Well.... My vibration is at 1 times RPM.
That would indicate rotational unbalance.
The faster the engine is reved.. The smoother it gets past 1200 rpm.

So? With this vibration I call a studder, shudder, maybe misfire?
I think the source of all this madness is the Torque Converter.....

Thoughts?

[67440Dodge]

Torque converter? most likely not.. if anything in that area was causing it, I'd lean towards the thrust bearing being wasted and causing a vibration.

Since you swapped out the intake and it seems to run smoother, I'd look in the direction of the upper part of the motor. Cam lobe wiped, sunken valve, vacuum leak, etc.