The 30 carb is a completely different animal from the larger engine carbs, wouldn't expect anything from the larger engines to be usefull on the 30. Could be wrong, been a while since I've checked but don't think UHP has a venturi for the 30.
Bob Z has had good luck with the stock carb wired to a set position. Personally, I would make an aluminum insert for the stock carb body with a 10-32 nylon screw opposite the needle/spigot to be able to adjust the choke area and eliminate any possibility of a variable air leak.