FAT carb

If you remove the carb and check the primary transfer slots,are they completely exposed? or just a small amount,if so your idle curcuit needs to be redrilled to allow more fuel through the idle curcuit,as you are running on the transferr curcuit and you most likely have a blown valve as well.This will allow you to close the throttle blades and the idle curcuit will start working again,mrmopartech