Which
3 circuits are for tunnel ram intakes with big plenums.
2 circuits are for throttle stop classes.
Most everything else uses a 3 circuit, trying to lean out the intermediate toward a 2 circuit.
Buy the 3 circuit and try it. Then increase the intermediate air bleed until it slows down, then increase the main jet and see if it goes faster.
Or buy a custom carb for your application from name brand builder.
Or buy a used name brand carb for a lot less.
Is that any better?