I rarely use the paper gaskets with the valley pan.

Curious what sealant if any you use, Dwayne.

Years ago I used “high tack”.

More recently I’ve used a very thin smear of black “the right stuff”.

I’ve run them dry as well....... usually when I know there will be manifold swaps involved.

Until I had things more sorted out, I’d remove the pcv valve and use 2 breathers, and lock out the distributor...... start out at like 32deg.

I'll try again tomorrow. I put the intake back on.

No gaskets and two beads of Right Stuff on both sides valley pan hopefully...

That's what I did, I had right stuff. I never used the gaskets in the past, Spray copper or smeared a thin layer of the ultra copper or something like that.
This engine i dropped the parts off to the machinist I've known for 20 years. I just wanted machine work, I wanted to assemble it. I never had an issue with his work, great guy. He talked me into him assembling it and run it on the stand, break in the cam.

Right on! Hopefully it will help the issues.

Any update?

Possible.... have you tried giving it more timing anyways until it breaks up? Ive had an MSD box play with my timing light and give a way off timing indication. also are you using a factory balancer and timing indicator??

I was thinking about the msd giving a false reading the other day. It's an old
6al. Maybe I'm way off on the timing. I hooked up the lm2 wideband yesterday and ran it. Light throttle it's 12.2-12.8. When i drop the idle down there is a point where's 1/4 turn on the idle speed
Screw just kills it, is that when it's switching over to the idle circut? It's
not killing it because It's closing too far, I Checked the transfer slot.
At that point when it starts to stumble and die it jumped up to like 15.2.

I did take the carb apart last week and write it all down, I just don't have that in front of
Me right now.

It's an aftermarket balancer professional products or something. It's not a
Big money piece.

sounds like the transition slot is keeping it running and as you drop the idle speed down once you get close to idle speed (and less of the transition slot is below the butterfly feeding fuel) it goes lean and dies.

i would turn the idle MIX screws out to richen it up (a good initial setting here is 1.5 turns out), start it and then drop the idle speed down to where it needs to be. then slowly turn the idle mix screws back in to find your leanest idle tolerance.