Don't forget your fittings! Kind of a generic issue regardless of manufacturer. I had 6 mm tubing throughout the suction side, but the vent and tank fittings and the UAT inlets were both 4 mm ID. Had trouble getting the JC 140 to spool up fully and the UAT was partially collapsing during WOT. Also, I had to fill the tanks sloooowly cause they would bulge during fueling. Ended up replacing all suction and vent fittings with high-flow fittings and putting in a high-flow UAT. Currently using 3/16" tygon tube for all runs up to the UAT. Then used 8mm with reducer to 6mm festo line from the UAT to the pump. No more issues and can fill as fast as I want to.