I ran 35 lb, but man don't buy a crappy brand, mine always break. They just break those little ring clips that hold the cylinder in. Of course its only when I try to show someone. Just go big and get the autolock ones. I am told that all you need is the 11lb, but I don't think a lil extra would hurt. Good luck.
i have auto loc 35 lb, and the eclip has fallen out twice and i havnt driven my truck since i got them put on. spal is much easier to install, and it will be better for the rainy weather because they got a rubber boot to protect them.