DragStuff

What are the advantages of running annular boosters over down leg boosters ?

I run down leg busters in my 1000 cfm HP Holley 4150 flange carb because the class rules are "4150 only". The down legs take up less area in the venturi and allows for more flow. My motor is relatively big (525 c.i.) for the carb I'm allowed to run. The carb needs to move as much air as possible. I also run nitrous which the carb with DL busters will help.
I sent my carb off to Pro Systems to be sure it's the best it could be for my motor combo.....

Annulars have a stronger signal, but will sacrifice airflow. The bleed size will change between the two. With your setup stick with the downleg, you should have no issue tuning if it's the combo on your signature.