I am in the process of modifying the fuel rails for my setup it will be a parallel configuration. I had it figured out but now I'm seconding guessing, I was going to install two -6 inlet's and two -6 outlets. But now I'm thinking that I should put in two -8 inlets to supply plenty of volume and leave the two -6's for return to the regulator. By leaving the -6 on the return ends of the rail it should provide some restriction and increase the rail pressure, or should I just leave it up to the regulator?

This is a high horsepower race application just in case anyone reads this and assumes its a DD

 

I didn't run a return off my fuel rails, on the outlet of my regulator I installed a Tee and supplied the 2 fuel rails and ran the return back off the regulator. I'll try to take a pic later.

 

The two -6 return lines wont really make a restriction when you are idling and when you're using lots of fuel, they will still be fine with -8 feed lines. Lots of us have done it that way. The regulator will handle the return flow and pressure if it is sized to do so.

 

Good deal, I will just use the the -8's to feed the rails then use two -6's on the outlet's
Which would be better, should I run the two -8 into a Y a use a regulator with a single inlet/outlet on the return side. Or use a regulator with a dual inlet/outlet on the return side. I would think the dual's would work better and be cleaner install

 

I ran two -6 lines from the rails to the regulator with dual inlets and then a -8 back to the tank, but that's cause I had a whole coil of -8 and -6 would probably work just fine.

 

Did you ever get a chance to take a pic of your setup..