For what it’s worth, I used a stock Hemi 3/8 hard line and for the return I used a stock BB 5/16 hardline run along side the supply. Keep it it stock appearing was in mind. I’m also using a Fast XFI so I plumbed in an E85 sensor just in case. I also have a special flash that has PWM pump control to keep the return flow in check. The pump I decided on was an OEM hellcat pump capable of supplying all the power you would need in an N/A engine. The tank I used is a Tanks inc. that has provisions for an internal properly sumped pump. The entire setup is whisper quiet. I have a pressure transducer to monitor fuel pressure but more importantly use it for the fuel pressure correction features in the XFI. Basically I think the system holds the pressure about +/- 1.5 psi, maybe even better.
AG.