Large rpm drop

OMM asked about converter brake stall.
That shouldn't effect idle or off idle much, because there's not enough to get it even close to stall speed.
BUT. I totally agree that a med stall speed converter is needed forthis engine. 2800- 3200 is a med stall range.
I was going to say that you should be able to run very quick advance since vacuum advance is not being used.
But with a stock stall speed I have doubts as to whether that would be true.
Anyway one step at a time. Get the idle and low speed, low throttle stuff figured out first. That's the foundation. Otherwise the engine is trying to clear up when you try to open up the throttle quickly.