I run a holley regulator and that is the suggested plumbing they included in the manual. The regulator has two returns and I have considered changing it to where it feeds each rail individually but I wasn't ready to spend anymore on the project. I had planned on going that route when I made the intake change but I had to spend $200 in fittings just to be able to use the lines I had from my old intake that was an expense I didn't plan on.

There is no reason for the curved crossover other than making sure I had clearance for my radiator line(closer than it looks in the picture). Also when I try and make an AN line to exact length it usually comes up a little short once it is all assembled, the curve gave some room for error.