Did you mean plug not plus?I use the C5 corvette filter/regulator and plus the return port at the throttle body.
In tank pump.
x2 I did that on my 68 earlier this year and haven't had any issue in the almost 1k miles I have put on it so far. I haven't noticed any issues with hard acceleration and around 1/4 tank of fuel.You can use Holley's 255 LPH OEM Style EFI Fuel Tank Module. No return necessary.
Is that plate just bolted to the tank strap?This is how I did my set up, I copied how Holley set up their Camaro. I also took Vegas$69 advice on running a filter / regulator.