We had a heavy field dynanmometer that had 2 big Cummins diesel engines when it was converted from gas to diesel. The gas engines were 500hp Ford engines used in the T23 electric tank.
We usually had a air problem when we changed fuel fiters on the Cummins. We took a fuel cap and welded a tube fitting on it and used low air pressure to force the air out. No problem starting after that. We would lower the air pressure on the regulator until 2 or 3 lbs were on the gauge. That fuel tank held 400 gallons of fuel, but the engines were mounted above the fuel tank. Hal