Well since you said that your Vacuum advance is plumbed to full-time vacuum, That could be your biggest enemy, cuz you didn't say how you set it that way nor how much the can brings in.
Notta chance would I run that modest cam on full-time VA.
I had it set to full manifold as opposed to ported from suggestions from a couple of people. I believe the can pulls about 26 degrees at full vacuum. It’s a MSD chinesium clone that didn’t specify. I need to take a peak at it once the engines warmed up. It did fix my off idle stumble when it was warmer but that’s when it was still 70 degrees, now it’s 30.
Here are some pics and will post the video in a minute.
Carb as it was when truck was shut off last night.
Throttle pressed to close choke.
Current choke setting, it’s hard to see but it’s on the second from the right, set to open sooner.