Chevrolet Repair: Old gas tank 1979 , electric fuel pump High PSI, electric fuel pump, fuel pressure regulator

Question
Van,
My son and I are completing a 1979 Pontiac T A Firebird and we need to use the high pressure electric fuel pump.  We need to use the 1979 fuel tank.  I believe a baffle is in the tank for the return fuel. question ? The high PSI return from the TPI 350 needs to return to the gas tank, return line.  Any concerns about pressurizing the 1979 fuel tank.  Who sells the high pressure fuel pumps.? I beieve the pressures are 28 to 35 psi. to charge the TPI, I do not know return pressures on un-used fuel.  Please advise as best you can .  Or direct us to the fuel pump guys.  Thanks  Bob & Phil

Answer
Hello Robert,
The fuel pressure regulator is the item that restricts the return of fuel to the tank, thus creating the hi pressure.
That pressure is just in the injectors, fuel rail, and supply line from the tank. The tank itself isn't pressurized, although newer gas caps seal evaporation pressure in, and force it to be recovered by the vapor canister. But that isn't pump pressure when you remove the cap. And your 79 cap is probably vented.
So the return line pressure will be pretty much atmospheric pressure, not any kind of high pressure.
Any baffle in the tank would be to reduce sloshing.
I would assume you will want to get an inline high pressure pump, rather than go inside the tank. I don't know for sure where to get them, but I would start at "O"Reillys, or Auto zone.
Good luck,
Van