Help diagnosing intermittent miss

[XH29N0G]

I am looking for a systematic way to approach diagnosing an intermittent miss that started today.

This morning I changed the oil and replaced the rotor on an MSD ready to run distributor.  Then I took the car for a drive, and it was fine up until the end, when there was an intermittent miss.  It may have started as I ran it up through 2nd on an on ramp.  I reved a little higher than normal, probably close to 5800 RPM, but it has seen that before.  It has a hydraulic flat tappet cam.  After this, I thought I noticed something like a miss in 5th cruising at 1500-1800 RPM but not at higher RPM.  When I got off the highway, I noticed a definite irregular, intermittent miss and I could see it on the tachometer (drop in RPM).  I did not time it, but I think it occurred too infrequently to be a specific cylinder missing every time it was supposed to fire.  Unfortunately, I had to go to work, so I put the car away before being able to diagnose it idling at home.

Earlier this evening, I checked the rotor and visually, all looks good.  Oil etc... are fine.  I just checked all plug wires and all look good. 
Next time I start it, I will check the wiring from the key because it has had strange behavior with the connection from the harness to the key - that seems to shake loose sometimes and turned things on and off.  I do not think that is what is happening now, but will check.

I know this is a short description with little information, but I am hoping someone can help and am looking for recommendations on other things to check.

I saw a thread from a while back about a bent pushrod doing something similar.  I don't want to pull the valve covers just yet, but will ultimately check that.  Are there other tests I can do to check?

Thank you in advance.

[c00nhunterjoe]

A pushrod wouldnt be intermittant. Start at the tailpipe and listen for which side its missing on. Narrow down from there to a specific cylinder. Then swap the plug and wire on the one missi g to another and see if it follows.

[XH29N0G]

thanks

[440]

I've used similar methods before to locate single cylinders by pulling plug wires off at the cap one at a time with insulated pliers and listening for a change or not