Fuel Starvation?

Gudday Mate,
You have basically the same set up as me. I run 3/8" line all the way through. I'm running a Carter electric pump mounted to the rear under body directly in front of the diff. I have a professional products inline filter after the pump and before Holley regulator. You will definitely benefit from the larger fuel line.
I'm also going to run a return line when I pull the motor for repainting. Two points being that with a return line installed, I can opt for an EFI fuel system in the future if I want and also the electric pump will run quieter.

Best of luck
Regards Pete