Did a spark plug change Saturday, got done do a test start/drive everything is fine. Hang out with my buddy for the rest of the day. On my way home getting on the highway I start to accelerate and I get a couple of hesitations and then a knocking, so I pull over into a gas station and think "what did I forget?". No wires were going to the wrong cylinder. After looking over everything the #5 plug wire isn't really hooked on, the metal clamp part was no longer attached to the rest of the wire. I get the car back to my buddies place to fix in the morning.
Fast forward this morning, I replaced the wire set, still knocking. Checked the coils for spark, plenty of spark from the coils and going to the plugs. Maybe there'* a bad plug or wire? After doing a lot of musical spark plugs/wires with a spare set of plugs and the old wires the problem is still persisting.
I have no DTC'*, codes, check engine, etc. It sounds like #6 is the culprit but with all the noise it'* hard to tell.
What else could be causing this?

If the knock only started after you did the plugs it should be related to this. Does it sound like an upper valve train knock. We can only guess on our part without hearing it.
Do you have a pencil type spark tester so you could test each plug for spark while running?
Its also possible if a cylinder wasn't firing the valve could have gotten loaded with fuel and got stuck. Add fuel injector cleaner as well as a crankcase additive.

I'll keep that in mind.
I'm leaning towards some fluke problem that cropped up that is completely unrelated to the ignition system. I tested the coils and they were all good. There is a definite metal clank going on that is really hard to trace. It sounded like it could have been coming from the trans, but the flex plate looked fine and after detaching the torque converter from it the noise/shake was still there. I also ruled out the SC.

My friend Tom was wondering if it may be something to do with the balance shaft as the sound seems to come from all over the block.
I plan to do a compression test tomorrow. I may end up just tearing the top end apart.

Compression test should tell you if its the top end or not.

Well after dropping the oil pan to check to see if there were any metal chunks there, nothing.
So my friend Tom(old gray haired shadetree mechanic) decided to forget the compression test and tear off the rear valve cover, as we both concurred that the noise was coming from there, to see what we could.
Yanked the cover and sure enough, we found the problem. Broke valve spring on the #6 intake.

Top part of the spring:

Retainer:


And of course the intake valve that fell:

The piston had a little bit of scoring, but from what Tom said(and Wren) it shouldn't be anything to lose sleep over.
Now to get it all back together!

not as bad as I was thinking it was going to be...



Those were CompCam springs right? How many miles on them?

Yup Comp Cam 105#. I don't remember the exact mileage when it all went in but I haven't put that much on. I'd guess around the 20k mark.

That'* terrible. Are you going to replace all of them for piece of mind? Intense warranty?

So it was a valve, only not stuck.....loose in the head.

What type of retainer are those?