Lovehamr
Your plumbing looks great. Do you have any flex line connecting the motor to the Alum hard line?
I built a return style system for my SPF last summer. I used -10 (5/8) stainless tubing terminating at the base of the firewall, with about 20” of Aeroquip AQP hose and XRP socketless fittings to the regulator, and -8 to each of the carb inlets. Then I wrapped all the hose in heat reflective tape.
It sure moves a dam lot of fuel at 6.5PSI!!
I built it with the intent of feeding my big EFI motor shortly. you can almost never have "too much" fuel system!! lol
Jason