Two stupid questions:

1) Stated above in post 9 jetmech05 says to use two clunks. Is this correct? One on the pickup line to the carb and one on the fuel dot?
2) When you refuel, disconnecting the vent line to the muffler, and using the fuel dot won't the pressure of fueling push some of the fuel up into the carb through the pickup line? Or does the clunk prevent that?

I am going to use this setup with my now completed PT40. And if all goes well I will be converting all my planes to the 3-line.