need some advice, running 3/8" fuel line, how to run, what to use

I think that's the route I'm going to go. Run right from the tank to the mech fuel pump with 6 AN. I'm running a 408 stroker so the HP will be around the 500 ponies if I'm lucky. IF I need to run an electric fuel pump I can add 2 feet at the tank to the pump and just move the line to the regulator off the mech pump and then to the fuel rail. Sound about right?

Sounds about right! I’d use a pre and post filter on the electric pump as well.