The main jet is adjustable that is what the needle is for, to adjust the amount of flow needed to keep the fuel at the proper level around the emulsion tube.
Remove the bottom of the carb disassemble then run a drill bit through the main jet, you will see it go through the jet by looking down the emulsion well. Start at 1/16 which is 0.062 you could start at 0.070 and be fine. That is what's nice about the needle is you can adjust it down if you get too big, if you go way too big it makes the adjustment real touchy, like a little turn of the jet changes the flow a lot.
For instance my puller is 436 cubes and I have the main drilled to 0.140 to get enough fuel. There is also nothing stock about my carb except for the appearance, everything inside is made to properly handle that amount of fuel.