Nothing fancy, a ~6 inch piece of 3/4" box tubing with four nipples welded to the side of it. The high pressure pump pick up is at the bottom and return to the gas tank at the very top, with the regulator return second from bottom and the lift pump inlet second from top. That way any air the lift pump sucks up when the pickup is uncovered when low on fuel goes to the top and is returned to the gas tank, and the lowest outlet is always covered in fuel for the high pressure pump.
Rebuilding an OHC Pontiac 250 with EFI and a Turbo