280z gas tank for triple carbs on FI pump

[Dat73z]

Hi all,

 

I am currently setting up a triple sidedraft carb blowthrough turbo project on a L-series and am working on gathering components for the fuel system. Here is my current setup as installed on the car NA with triples: 

 

1) 1973 240z gas tank

2) Rising rate Mallory/MSD bypass FPR (Return to top vent on tank)

3) Carter 4070 Fuel Pump (Using stock feed)

 

Here is what I have available to me: 

 

1) 1975 280z EFI gas tank

2) Rising rate bypass FPR (could use existing Mallory or similar...need to remount in engine bay for vacuum line)

3) FI Fuel pump selection

 

Here are the Q's:

 

1) I'm looking to run a Walbro 255 or similar (http://walbrofuelpumps.com/walbro-gsl392-inline-fuel-255lph-pump.html). The rating for the pump is 43-87 PSI and I'll need to regulate it down to 3-4 psi to run the triples off boost. Anyone ever try to regulate down a FI pump to carb pressures and if so any issues there? 

 

2) I'm debating between running the 75 280z EFI tank, modified 240z tank, or a custom tank. Don't want to run a fuel cell. With the stock 240z tank and the carter pump on mallory regulator I was initially having difficulty regulating the pressure down to 4psi using the top 1/4" vent as return on bypass. I am assuming with the rising rate bypass FPR I don't want to put a deadhead regulator before the carbs as I'll need more fuel pressure on boost. Any thoughts on plumbing the bypass off reg to the stock 280z tank return? Not sure if the return diameter is sufficient to keep the off boost fuel pressure down or I'll need to modify the tank anyways. 

 

Thanks!