[Luce]

What I did on the wife's c3 that worked great was kept the original (not factory, but...) mechanical fuel pump and added a surge tank where behind the drivers wheel well. Put a walbro under to feed efi, regulator return goes back to surge tank. Then the excess volume from the surge tank goes back to the tank via the old vent line. Without a float, the mechanical pump keeps fresh cool fuel in the surge tank, full to within 1/2 of top giving 1.5 gallons or so reserve if the mechanical sucks air. So I didn't have to mess with the original tank.

Also, there's a filter between mechanical pump and surge tank to keep debris from original tank out of the surge tank.

In my cobra, the surge tank is inside the main tank, kept full by venturi pump fed by return. Also has trap doors keeping fuel in middle section of tank. Never had any starvation.

Get it in and tuned and you'll love it.