motoxlifer is correct. That is how I'm set up, fuel to regulator and excess back to tank. Ya, I paid all that money and still problems!!!! The fuel regulator doesn't work and now one of the damn header tubes hit a plug wire!!! I pretty much lost it last night! If I try to reverse the lines, they won't fit the coil covers right. I would have the return line going through the notch in the cover. I might reverse them for the hell of it just to see what happens but I wen't by their instructions. I know what your fixing to say Greg! Don't go there!! LMAO Wait until S&P gets my phone call this morning. I've sent them pics and showed them exactly what to do and they've missed it every time! I'm leaving this header on just to crank it up and drive it for a couple of day's but they're gonna have to send me another header. I think I'll build my own headers next time!!