I've got a question, The Holley Blue fuel pump comes with the 12-803 regulator, which doesn't have a port for a return line, so do I NEED a return line? What happens if I don't run a return line?

 

it is better to run a return. it is easier on the pump. use the search i did a thread on this type of mod on my 84 gsl

 

I need a straight answer from someone.

I need to upgrade the fuel pump. I can walk into a shop today and buy the Holley Blue with the 4.5-9 psi regulator. Is 4.5psi too much for a Weber 40IDF, or is it just right? With this setup I cant run a return line.

Or should I order a Holley Red with a 1-4 psi regulator? With this set up I can run a return line.

 

There are 4 related threads at the bottom of the page that go over these questions. The answers have also been covered in the previous threads that you had started on Weber questions and fuel pressures. There were even links given on another thread that you started to optional fuel pump usage.

The answers are there and you need to start getting them. Many members have gone and taken the time in previous threads to help you.