i just finished this kind of setup . i kept it stupid simple .
2 tanks . pic a side for primary with psi pump specs the efi needs . it gets the job of the efi system only .
other tank is a transfer tank with a std tbi pump on it .
send fuel over to the other primary tank and tee in to the filler neck vent hose right at the tank as its all up hill from there to the filler neck / cap area . fuel has to go down hill in to the tank .
next i rewired my indash switch for power feed out only to transfer tank .
next i installed a seperate gauge ( if you want one ) and a BIG red light that only lights when pumping fuel over .
i tried it for the first time yesterday and was impressed . no waiting in line at the fuel station just pic a pump with 2 tanks . just so happened i had pass side open and mine is the transfer tank on the pass . i filled it up full . took off down the road and flipped my switch and in 5 miles my driver side tank went from 1/8 to 3/4 tanks .
this is just my simple what i had version and do as you wish . good luck and remember to double check them fuel lines for leaks
