Here is a photo of the nipple modification I use on the Tee Dee and Medallion. You screw a 2x56 "T" nut onto a bolt and chuck it into your power drill. Use a file to cut the flange down until it is a nice hose nipple shape. It will then screw onto the plastic nipple on the carb housing of either engine, and if you use a bit of Goop, epoxy, or JB weld, will seal perfectly. Drill out the tap per factory instructions, and you have a very reliable pressure tank drive system.
I like the ultra fine control that the Kirn or Klaus needle system provide, but it is quite workable with the stock needle. I seem to need about 1 ounce of fuel to do the classic pattern on 42.5' lines with a bit of margin left over. I do tend to set it screaming all the way, keeping attention on not going over-lean on the verticals and overheads. If you want something closer to a 4-2-4 break, you will need a bigger tank. Currently, I like the APC 6x2 prop to give me lap times in the high 4-second region.