Trust me when I say I've done more street/strip testing in the last few years to wear my junk out and I NEVER see the need for more than 2 e-holes so far from dragsters, truck pullers, boats, drag week etc. But I use a certain BLP booster with 12 .059 holes and as Mark W. has said, he uses 3 smaller .020-.021 and more/smaller holes in his boosters. When I've added a 3rd e-bleed the carbs go dead rich and the curve is not as flat as with 2 all day every day on MY junk and in carbs now all over the globe..........Some days it's taking candy from a baby easy and others, drive my crazy as even deeper into what the hell just happened there........... Same for 3-circuits, never seen a need yet at 1100+ hp and n/a 8-second et's and recently I converted a BLP 1.720 bore 3-circuit 1050/1200 for a BB Chevy dragster who was going 4.80-4.81 w/a 1.10 60 ft. who now goes 4.60 and a 1.06 60 ft picking up 3 mph......