fastrrrr

HELP!!! I have a 35' Velocity (tbred) with 525SC's that have been giving me fits. My problem is one of the engines use almost twice as much fuel as the other. I have rebuilt both engines/carbs/superchargers. Replaced fuel pumps and pluming. I have even changed one carb and put it onther engine to see if it used more fuel. I fill the tanks up (two separate tanks) and one reaches empty long before the other. Anyone out ther had this problem? Last year I blew an engine and the machine shop told me it was likely because of a lean condition (guess what....it was the engine that uses less fuel). Any help?