I tried combination #1 because it was a lot easier and allowed me to use fuel hoses I already had.  The people at EI Instruments thought it would work, and it did, some of the time.  I wasted a lot of time tuning and trouble shooting because although it “ought to work” it didn’t.

Combination #2 was officially recommended but a major pain to install and involved 2 new hoses.  I check the totalizer every time I add fuel and it is within a few tenths usually or a gallon and a half rarely.  That variation could be from how full the tanks were at the last fill up vs. the latest fill up.

RV 6 with O360 carbureted

#1 Boost Pump-Gascolator-Transducer tilted about 30 degrees uphill-Engine Pump

#2 Boost Pump-Gascolator-Engine Pump-Transducer (45 degree fitting to inlet, transducer mounted level, 20 degree bend in exit line about 4” long, 90 degree fitting to the carburetor

Steve Colwell   Legacy  (Hysoling in the emergency access window frame)