I have Andair PX500-TC Pump for 1/2 "Fuel Lines and my fuel lines are 3/8, my solution is the one I show in the photograph, there is a better one, there is a problem that the fuel line is smaller That the bomb ??
Note that even though the inlet to the regulator is a -8, the chart shows that up to 350 HP can be fed with a -4 fuel line from the pump. Automotive systems typically operate at around 40-45 psi, but even at the a/c norm of around 30 psi you should still get plenty of flow with -6 lines.