you read my mind, thanks - I was just reading through that post right now in fact.
Reading your post and watching a few videos over some time here.. sounds like float level. This carb doesn't allow me to adjust the floats from the outside of the car - i'd have to take the bowls off and manually bend/adjust a bracket that holds them from the inside. this is sounding like my issue. I checked the idle screws and they're at 1.5 turns out from all the way in. Sounds like floats.