I had to Repost This Question because I think the 1st one was a little too confusing When I read it over.
But, I'm still in the Process of Rebuilding My 3800 Impala Engine After having persistent Cyl 5 Misfire, A little history: I Replaced everything relating to the Cyl 5, But to no avail. So when I opened it up, I found Oil on top of the Lower intake Manifold, Seems a common issue with these engines. My Throttle Body To Upper Intake Manifold gasket Looks Warped from the EGR tube Heat (which I suspected is where the coolant Was getting to the Oil from)
I provided a link at the bottom of a Video that I uploaded, In the video, My Rockers and Push-Rods have play in them, (the Rocker Arms Slide from side to side, even tho its not very much, But it worries Me, Also, I can Spin Around the Push-Rods with ease especially Cyl #5 Push-Rods), I haven't gotten to the Rear bank Yet, But I'm guessing it'll be the same scenario back there.
I though of Just replacing the Lifters and corresponding Push-Rods that had play in them (as a cheap fix), but I figured that won't be a good idea.

So My question(*) is, are the play that I'm having in those Rockers and Push-Robs a common thing to see in these engines?
If not : (1) what would be a good way to diagnose what My problem is while I have the engine Open?
(2) What extra step/check can I do while I'm inside the engine to See what else I need to perform a good fix? Is it worth it dropping the Oil Pan and Checking the Bearing for any Play too?
And (3) If I don't need anything else, Will Just Replacing ALL Of the Push-Rods and Lifters Fix This Issue For Me?
Thanks.

Link to Youtube Video : Play in Rocker And Push-Rod Video Misfire Video : Knocking Video -

I believe side to side play in the rockers is normal/intended. Reason your not getting play on the other 2 is because they are under tension.

Oil in the bottom corners of your lower manifold is normal also.

The last video with the oil fill port, this is a tough one. A rod knock sounds like dull heavy metal hitting dull heavy metal. You can feel it throughout the whole engine. 3800'* are notorious for having rod knock if the crankcase is filled with coolant(usually the intake gaskets cause this).

I'm wondering if you have collapsed lifters on #5. Pull the rockers off and see if you can "squish" the push rods into the lifters.

Either way, the engine doesn't sound right. Pull it, and strip it down. If your not familiar with even the BASICS of engine rebuilding or don't even own a micrometer, this project isn't for you. Find a junkyard, spend $500 and get another engine. These things are a dime a dozen anymore.

Lolz, Mike, I Have Dealt With Engines Before. I did Engine Conversion in My Dodge Intrepid From A 2.7L To 3.5, I Stripped it Down to the Block Before Swapping. So I got quite a bit Knowledge Of How things go in there. But I'm going to do what You said, about squishing the Lifters, I'm Leaning Towards Collapsed Lifters Theory, Which is What I'm thinking of Replacing, Along With The intake Gasket & O-Rings and Such. Cos the car was Running Fine, Just that Misfire, I must Mention, the video with the Oil fill port was before the one for Misfire, Cos after I changed the Oil, that Chirping Noise quieted down alot, Just the Misfire Persisted. But, let Me share a little bit of My Findings/Conclusion looking back in Retrospect from when I initially noticed this problem; So sometime when the car was running fine, it started burning/Using oil that I had to keep toping it off (I can remember one time this guy told Me that My Tail Pipe Smoke Smelled like I Was Burning Coolant, But I was adamant to take that hint/Advise), Also at that time I wasn't very Familiar with this Engines. Now I reallizes That Was My Cue, that was when I should've went and changed the Intake Gaskets, But I didn't.) Plus the car had no power at all (Which now I know is a very clear symptom/indication of a car with Bad Intake Gaskets) I even went and Dyno tested it, power was at like 168whp if I remember correctly, which was Really Poor.
But anyway, leading up to when it started Misfiring, One day, I was driving something ticked Me off and I went and checked the oil dipstick, oil was like dangerously low, like at the tip of the dipstick, so I stupidly dashed into a nearly by gas station store and bought some 5W 30 Oil Without realizing it was Regular/Convetional Oil (While I always Ran MaxLife Syn Blend W/O any issues) So My Guess is That'* Where everything went Down south Uptill today, Leading to Me Changing the oil, Went back to MaxLife Syn Blend, then 95% of that Noise Went away, Then all I could hear Was Like Light Tapping Sound.
So I hope this info can help Give More insight on Which way I Should be going...
Thanks.

But also, in the mean time, in between time, somebody did mention to be that I Should do a compression test, and that'* what Im trying to do. Right now, I have the Upper and Lower intake Off. So can I still perform the Test? I'm armed with a Compression Tester Loaner Tool Courtesy of Auto Zone, Lolz. So I wanna know if it'* Possible or Not?

Yes, its possible, just pull the fuse for your fuel pump, otherwise, you will have fuel all over, have a good power source hooked up to your battery and make sure all of your spark plugs are ALL out at the same time.

Mike, what about coolant?

He'* not starting it. As long as it has oil, it will be fine. He only needs to turn it over about 5 compression strokes to get a good reading. Taking the time to move from one cylinder to the next allows things to cool off a bit.

No, I am talking about all the coolant openings he has, when he rotates the engine, the water pump creates pressure while cranking, coolant will come out of the openings....now that I think about it, he could just remove the serp belt....

From the looks of it, he drained it. But yeah, good eye sir. My dumb *** would have cranked it over. LOL.