What style fuel line is best?

nice ! You built a nice fuel system, fuel starvation will not be an issue.
I used 1/2" in my system, took the advice from an old timer. He said spends your money once and build it right.
You need 1/2 to feed over 600 hp in the 1/4.
Thank you. The fuel system works pretty good as far as I can tell. Having this 1" thick wood spacer REALLY keeps the carb cool to the touch. I'm a believer.

AED Birchwood Carburetor Spacers 6170

Very interesting
Almost looks to me, like you would have max psi going into the carb, and regulated psi back into the tank
(Obviously it works, but I dont see how)
Have you had a fuel pressure gauge on it, and verified it reacts to changes on the regulator?

At first that's what I thought. But it works and I don't know how. lol. Someone on here explained it to me, I'll search for the thread and get an answer. I have a gauge mounted on the fuel log, its not in those pictures. The way I have it, it works when I adjust the regulator for any given pressure. :)