Gasket blown? Yes. In probably 4 different places. There was oil coking on the gasket surface over multiple spots and fresh oil on the plate.
Miles? Unknown. OD read 305, but this whole engine is full of original mopar gaskets and it holds good compression. I'm guessing around 120k, but that's just a WAG.
Replacement: I checked the bolt fitment for bottoming and they all ran down to the plenum, bottoming on the washers not the threads. So, the bolts are fine.
I just cleaned the surfaces well and used the fel-pro gasket. I used red loctite on the bolts, but the fel-pro gasket is engineered to not need silastic rubber as a sealer. So, I put it on dry and torqued it. I do the same with the intake gaskets on the ports and the timing cover. No leaks. Don't believe me, call Fel-Pro and ask them.
The plate looked straight, and checked out fine with a straight edge. The gasket I took off was the metal one, factory I suppose.

I'm on the hunt for an M1 or Air-Gap, so if it lasts 20k more I'll be fine with that. I'm also thinking about welding injector bungs into a carb intake as a fun project and a way to make a budget version of the M1 from a different product with a lower cost. But the injector placement is key, so it really needs to be in a jig, tigged by someone who really knows what they're doing.

I'm using the Fel-Pro gaskets on the ports again (not re-using, new ones) because I was really pleased with how well they sealed. I need to get new bolts, I guess. Bummer. These have maybe 100 miles on them since I installed the EQ heads. One of the errors I made was thinking the gasket was fiber or composite material, and I could eyeball the perimeter to look for leaks. I had no idea it was both original and metal, and didn't think to look. I eyeballed it and it looked fine without a ton of oil in the pan. It started whistling on me when I got the engine back together and there was nothing for it but to get back in there and replace it.



Plenum cleaned with new gasket in place.

 

Posting mine up. Symptoms include: marble sound under load, excessive oil consumption (1 quart every 100 miles), general lack of power. Hoping to see if this fixes the issue. I am replacing te PCV valves and the valve cover gaskets