I've a custom fuel rail with return pipe + AEM FPR.

Now, I just need to route the return line back to the tank.

What hose material and diameter is good for this purpose? What to avoid?

For easy installation, I plan to use flexible pipes and zip tie it along the fuel delivery pipes under the car.

There's an in-tank FPR that I'll need to take out or disable, does anyone has experience with this?

 

-3 AN SS should be good.

 

Just curious what type of project this is?

 

-3an is too small for a fuel return line

try -6an or better yet -8an