The Pro Shocks are
oil filled not gas. Not sure if it would make a difference weather body is up or down. Mine are down. The spring rate is 375# for sb and 500# for bb on the fronts and 250# on the rears. I have not noticed the adjuster ring to move at all without being manually wrenched with most of the vehicle weight lifted, with enough weight lifted they can be turned by hand. I did spray some silicone lube to make it easier too. If you do a search there are some threads from CRII with recomended info from Don Scott.
John