The first example is the correct way. The valve has a ball inside that must be at a 55 angle to flow (roll) and seal properly.
I dont know if you can see the photos in this link but it will give you a good visual.
http://www.themalibucrew.com/forums/...nstallation-r2
It has worked flawless for me. I trailer and after filling up I would always watch the gas pour out of the overflow, now it all stays in the tank.