Thanks for the tips. I currently have the carb off reworking the vacuum lines and checking everything for leaks. I'll get it back together with everything cleaned up and double check what it is doing.
When I would drop the idle below 1000 rpm the only way I could keep it running in gear was to blip the throttle and the accel pump would provide fuel. The problem was not quite as pronounced when the trans oil was warmed up.
I'm leaning towards it being a converter that is too large and/or too low of a stall speed for my engine's torque.
My engine guy suggested going old school and trying a Vega converter which is basically just a smaller diameter and will raise the stall right?