return line for EFI conversion

There are many ways to plumb these.
I recommend a new 3/8 feed line and a 5/16 return.
For the return back to the tank you have a couple choices.
You can T into the filler vent tube but extreme caution must be taken to NOT cause any restriction for the vent or you will never get it filled at the pump.
I have found thin wall copper tubing T works good.

Another option is to log on to Summit or jegs and pick up a ready made filler hose return T.
Just cut the filler hose, insert the T and plumb the lines.
Clean and simple.

The pump is designed to push not lift or pull so it should be low and close to the tank.
The frame just ahead of the back tire works good.
Allways run a clear filter ahead of the pump. Fram G3 is 3/8.

I use universal steel prake lines for the new fuel lines. if needed, cut one end and remove the flare nuts and then double flare to help keep the hose in place under pressure.

Any restriction in the return increases the inlet pressure. This makes tuning a nightmare.