best mod I've made
I love those quick disconnects. It's so easy to pull the tank.
The crossover line is smaller than the other lines. I just used regular 1/4" fuel line, but the other line was the expensive fuel injected stuff. The parts store didn't have the 8 mm, so I got some 5/16" line. It's almost the same.
I don't recall a ring underneath the stock clamps, so I don't think I used them. As far as tightness, make it tight enough to not leak and loose enough to not deform the line. It doesn't take much, especially on the barbed fittings. Just a little tension will do. No need to crank down on any of them. Just snug them up.
Definitely use fuel injection clamps, and not the regular little clamps. Put it together, check the clamps in a few days and you should be good.