Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

flathead31coupe said
I was just wondering and where can you go with a return on a factory tank? I don't have any more room on my sending unit to make it any bigger if I need to . Someone said you can go into the filler neck but I don't know

I weld a fitting in the upper corner on the passenger side of the tank.