Put a new BPE 383 stroker engine in my 89 Iroc with a carb setup...problem I am having is having to re set the Holley fuel regulator 12-841 to 6psi each time I start the engine...sometimes it will be on 6psi other times the pressure will be below or higher than 6psi...have 6 an fittings for the supply...the return is 5/16 which is stock on our cars...is the return to small and should I go to 6an lines or 3/8 hard line...if so may buy a new metal fuel supply line 3/8...Called Holley and someone is to call me back...Thanks Larry

 

Update: spoke to Holley and was told the return line needs to be as big or bigger than the supply line...

 

You didin't say how much above or below set pressure it goes. If you are in between 4 & 9 you should be good. I have a holley fuel pressure regulator on my 91 and I am using the stock fuel lines, pressure & return.

 

It goes as low as 4.5 and high of 7.5 psi...will put a new 3/8 line for the return see if it stabilizes the regulator...thanks for your response...

 

What is your fuel pump setup?

 

Update: Replaced the Holley 12-841 regulator with a Aeromotive bypass regulator #13220...has two stages one Aeromotive 0-100 high pressure guage #15633 too a low pressure 0-15 psi guage...have the high pressure guage #15622 set at 14 psi and the low pressure guage at 6 1/2 psi...the pump was putting out 70 psi...I drag race my Iroc and needed to be sure I was getting the right fuel pressure without any pressure fluctuations...wasn't cheap but well worth the money...I also increased the return line with Evil Energy nylon braided fuel hose to 3/8...