I have a G-62 in a 29# Sea Fury. Flys the plane real well and I needed the nose weight. Engine is fully cowled so air to the carb only comes in from the cowl to spinner opening. Was getting real bad carb blow by(fuel all over the inside of the cowl). Engine was on the rich side, don't want to overheat and dead stick a 20# warbird. Turned a 22X10 Master air screw @ 6700. I added the B&B stack and the oil mess stopped totally. New RPM was 6300. Engine was now way rich due to fuel going down the carb and not out into the cowl. Have tweeked the needle and now have it back up to 6500. I will give it another 1/16th turn in and see how it goes.
Plane was clocked by radar gun flat and level at 96 mph with only 6500RPM so I' am not after more speed just a better fuel ecomomy setting. W/O the stack I could only stay up 10-12 minutes before starting to land on a 24 oz tank. Now I get 15 -16 min. with 4oz of fuel to spare.