Thanks for the comments. Definitely not pcv. I’ve come to the conclusion that the intake will likely be coming off this weekend.
I might just put the single plane intake back on.
Will dry fit both.

if you take the existing intake off clean the intake gasket surfaces real good. do the same on the cylinder heads. put the intake back on and just put bolts in the corners of the driver side and one bolt in the corner by the distributor on the passenger side. don't torque them down; just enough tension to locate the manifold. then take a .010" feeler gauge and run it along the top side of the intake and bottom side noting anyplace the gauge will slip thru. pay special attention to the #6-#8 area. if you have one of those flashlights with a flexible light to run thru the valley area it's a big help. be patient doing this. also look at the intake just below the #2-#4 ports and #5-#7 ports to see if there's a cast in extension that hangs below the port window. i believe those "extensions" at the gasket surface mess up a good seal with the fel-pro gaskets. i know 6pak intakes and a ch28 intake i'm using has them, also factory iron. i have an old ch4b that doesn't have them and it fits perfectly. anyhow, neither of my 6pak or ch28 have those problem areas anymore. i've used rtv for a gasket sealer before and generally rtv and gas don't get along well, but i have found the ultra gray to be an exception and it's all i'll use now. i also think you have more than an oil leak problem looking at those plugs. after the intake problem is solved i'd do some serious tune-up work.

Make sure your intake bolts are not bottoming out threads on the top of the intake ports, I’ve had this issue with aluminum heads and ARP intake bolts with some intake manifolds, an RPM will probably be OK but some old single planes like the Torker or TM7 have thinner flanges

Also, while the intake is off I would measure the intake to head angle. The best method I have found is to use something to space the intake off the head. You can use thin washers, but check the thickness because regular washers can vary by .005 or more. I use the paper gaskets and “cut” a washer from the bolt hole. This works great because a little bit of grease and it will stick in place, and won’t bounce around if it falls into the valley. Its also the right thickness.

Then i cut some strips of solder and use grease to hold them on the outside of the #1, 7, 2, and 8 intake ports. Install the intake carefully and torque evenly, 25 ft lbs is good for aluminum heads. Remove the intake and measure the crushed solder at the top and the bottom. It should be crushed about .002-.004 more on the bottom than the top. If you add the gaps from the pieces across from each other (i.e 1 and 2 and 7 and 8) you should have .006-.008 more crush on the bottom than the top.

If you don’t have more crush on the bottom it can pull oil.

Update. Prior to pulling the intake, I inspected the corners and the front right was in contact with the front crossbar and bolt head. The casting flash has now been ground back (at all corners). When intake removed, there was noticeable oil at all four sets of runners. There were gaskets below and above the valley pan, total combined thickness measured 0.07". Cleaned everything and mocked up dry, no gaskets, and the intake set very well. Ran a .006 feeler around everywhere and didn't find any gaps. Bought a new gasket set (Felpro 1214) and have installed the intake and new plugs. Did not get the carb back in place yet; Edelbrock Thunder Series 800 cfm - set at "out of the box settings". Will fine tune when I get past this oiling/plug fouling issue.

Did a lot of reading over the weekend and I dismissed the PCV valve too abruptly; as many suggested....my bad. Thansk to those who raised the warnings! The reason I was quick to dismiss, was the PCV value is new (supposedly factory correct replacement, 3 ribbed) and I recently had it and the hose removed to do some tuning with a vacuum gauge. I removed it to plug off the carb PCV inlet...chasing a "vacuum leak"; consistent variable vacuum of about 2" (10" to 12" at idle). The PCV was working and the hose was not oily at all. I have vintage 1970 CalCustom covers and they do have baffle plates.

However! I remember that when I stuck my finger over the PCV value inlet while idling 800 rpm, it sucked the crap out of it and I remember thinking WOW! at that moment; then went on without thinking anymore about it. My idle vacuum is a bit low at 12" (maybe not so low with the XE274H), but it builds to 15" at 1500, 18 at 2000-2500 prm and stays max about 20" up to 3000+ cruising. I running 3.73s so 3000 rpm is about 65 mph. 20" of vacuum all the time could suck a lot of wet vapors.

So, I don't want to go down this oily path again. What action should I take now to address any PCV issue? I do not want to install a liquid-vapor separator. Have read to add a inline restriction of 0.06" diameter (1/16") orifice in the 3/8 tubing. That is awful small in comparison to a 3/8" ID hose, and is there any "science" to it? Would it draw enough crankcase pressure out?? How do you have "correct" PCV on a performance engine?

M/E Wagner Dual Flow Adjustable PCV Valve?? I'm all ears.....

Sounds like the PVC Valve is working like its exactly intended to do

It should bee sucking your finger like mentioned at idle - And the hose was dry inside

And you said you have baffles in the valve cover under the PVC Valve

I mentioned the Intake Flanges on 9-01 possibly hitting the hold down bars with that intake manifold

And with you finding all that oil inside the intake ports , i would say with confidence you found your problem

Now that you cleaned up / grinding the flashing on your intake manifold corners next to the hold down bars and confirmed that is was sitting flush with the tin valley pan

I would put it together and run it

Looking at that picture again , i cant believe how close that hold down bar and bolt is with the intake manifold flange itself

My 383 / 432 With E Street Heads and Aluminum Intake isnt remotely that close