Car dies in gear...

In order to get my RPM where I needed it without opening the primary transfer slots up too much, I opened the secondary plates a bit. I'd double check your idle mixture screws with the vacuum gauge or tach. I got a more accurate reading adjusting mine to maximize the RPM with my tach set to low RPM so I could see the smallest increase/decrease in RPM while adjusting. With 18 inches of vacuum, I would not go lower than a 6.5 PV. What do you have installed now?