I don't know exactly how your T337B fuel system is configured, but with your help we can probably decipher it.
The fuel management piece you read was not the result of extensive research by me, but rather the result of a careful reading of my airplane's POH, along with some consideration as to how it applies to various situations.
First, in your POH, look carefully at the diagram of the fuel system and also at the markings on the airplane next to the auxiliary pump switches. This will solve your question of whether the pumps work on the auxiliary tanks or only on the mains. Moreover, it will tell you if the pump is associated with
an engine or with a wing.
Now, read in the POH anything related to fuel, including crossfeed operation. This will tell you if indeed fuel goes into an engine at twice the rate needed by the engine (with the excess sent back to a tank via the vapor/fuel line). To see what tank the excess fuel goes to, look again at the POH diagram for the fuel system and follow the return vapor/fuel line. I believe that you will find that indeed roughly twice as much fuel goes into the engine and that the excess from the front engine (regarless of what tank it is feeding from) goes into the left main tank, and excess from the rear engine goes into the right main tank.
If you have trouble figuring all this from the POH, you can scan all relevant pages and send them by e-mail at the address posted at
www.SkymasterUS.com or send them by fax to me at 305-668-7863.
Ernie