Up sized Return line connection

[69RSCLONE]

I decided to redo the fuel and brake lines on the car while the body was off the frame. I went with a 5/16 for the return. What is the best way to attach to the regulator? An adapter fitting at the regulator to a -6 and braided hose to the hard line at the frame? Or try to attach to the factory flex hoses? Are they to restrictive? Only running a 255lph right now and have trouble getting fuel pressure down to 42. But the lines were gummed up and rusty. I've read about drilling out the Saginaw fittings, but can't find out what is actually being done. Even if the mod is done, will it flow better, or is there restrictions between regulator and the end of the hose?

 

[GNVAIR]

If your fuel pressure is stuck and you have ruled out the regulator then blow out the return line in both directions with compressed air. Disconnect at the regulator in front and disconnect at the tank in the rear. I had this problem as did some other people who post on here. Guys run 9's on stock lines.

 

[69RSCLONE]

The old lines are already out and new are in. Just need to connect to the regulator. I am fine pressure wise without the hot wire attached. Once I get higher voltage my base pressure rises. I have to adjust pressure under boost not at idle. Example, should have 42 psi at 0 boost, and 62psi at 20psi boost. I set the 62psi under boost, not idle because it hangs around 42-44psi. With line off or on. Without the hot wire I can go below 35 psi. Pump and regulator are a year old and installed at same time.

 

[GNVAIR]

With vacuum applied at idle the fuel pressure should drop IF the regulator is working properly. When the return line is restricted it will stick at a high value such as 50 psi in my case. I tried 3 different regulators and different gauges to be sure and the results were all the same. I blew compressed air into the return line which dislodged the restriction and allowed me to get the pressure back to where it is supposed to be.
The fittings at the engine end are Saginaw fittings that utilize the o-ring. Some hydraulic flaring tools can duplicate this. The other option for you is use something like this that matches the one on the regulator http://www.ebay.com/itm/Edelmann-39...m33a9b3c18f:m:mXSwfW0u1biQ6CTcRw3vX1Q&vxp=mtr
If after doing all this and you still can't get the fuel pressure to change I would replace the regulator as your setup with the 255lph pump and hotwire kit is no different that the rest of us run.