Question 1.    Larger 1/2 inch fuel lines seems to be what people like best for supplying fuel.

What about the return line (line back to the tank) …Is there any benefit going with a larger return line? 

(Maybe to relive pressure as return line enters back to module with a small but OEM 5/16 fitting,  or maybe the return line needs pressure?)

 

Question 2.  I'm having a hard time looking over and down at engine...In the pic, the return line is the lower one right?  (top is brake line, middle hose is supply line and lower line is return?)

10 hours ago, 015point9 said:

What about the return line (line back to the tank) …Is there any benefit going with a larger return line? 

 

I'm fairly certain this one can be left alone. You would have to have an impossible amount of fuel flow returning from the VP to have pressure issues on the return line.

 

Can't tell from that picture. Follow the return line from the VP44, to the return line tee at the back of the head, and from there it heads back to the tank. Conversely, if you follow the line from the filter housing or pump (I forget what's first in the stock setup) you will see which one is feed and which one is return.

Top is the brake line, middle return to tank, bottom is fuel supply.  With the Fuel Boss pump I use the fuel supply line as a return line T into the filler neck. 

Basically if you're using an aftermarket pump (fass/airdog), it's best to return fuel from pump in 1/2" to keep psi swing down. Return from head and vp don't mess with. Reason you want 1/2" for return, if you can return it in 1" for example them fass or airdog will be happy it's how they regulate pressure, ball and spring, whatever doesn't get used flows to tank, but if you pinch it off now you got all that extra pressure going to vp, and that's why those that don't do it correctly have trouble with wild psi.

Won't do you any good to change the return fuel line sizes. If the port coming out of the VP44 is already small there is nothing to be gained. Return port is on the left and supply is on the right.

 

 

Thanks to all that responded.  I learned something.