Ignition or Fuel?

Your idle is way too high. You're probably already into the mechanical advance and you're not on the idle circuit of the carb. That will cause mixture issues and the adjustment screws are not as effective if at all. There should be no vacuum present at the ported vacuum port. My impression is the timing is way off. With your parts that engine should idle smooth as glass under 700 and be able to pull away from a stop just fine. You dont raise idle speed to make a stick easier to drive if that was the impetus. I would verify the TDC mark on the balancer for starters. Then make sure the distibutor drive is in properly, then set the idle speed for 600 and then set initial timing at 18°. Adjust the carb for best idle vacuum (gages are less than $10 anywhere) at 600rpm. Then raise the idle to 700 and test drive it. Thermoquads are very good carbs when properly set, and Demonsizzler is one of the best. But when things are off they can be very finicky and MP distributors usually need some sort of tuning. Which leads me to believe it's a simple tuning/setup deal.