Stainless Lines

I'm going to run all the lines down my frame with stainless, including the fuel lines. I am planning on having fuel injection, so I was wondering what size lines should I use for the feed and return?

well that depends on your set up. Which you did not specify.

But for GM all is good with 3/8 feed and 3/8 return.

I'm not totally sure of the setup, but I do know that with fuel injection, I would need a high pressure fuel pump. I kinda figured I would need 3/8, but I thought I'd ask to make sure. Thanks, oh and it is a GM small block prob with tuned port or TBI