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

I knew that I read that in your last post. I was wondering should I come from up front on my regulator by the carburetors or block that one and use the return at the pump?
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