Our shocks can be mounted in any configuration. Body up or body down does not matter.
On non-canister shocks, compression is the knob that is perpendicular to the shock body. On canister shocks, compression is the knob on the canister. Rebound (extension) adjuster is located on the shaft assembly.
You will need a nitrogen fill/check gauge. You will want to check the pressure with the shock fully extended. As the shock is compressed canister pressure goes up.
We usually start at 80 psi.
Can pressure is direct relationship to the force of the canister shock shoving it self apart. As can pressure is increased the shock will theoretically store more energy and create more rod force.
Most common gases we use in the shop are Co2 and Nitrogen. Our fill kits are Co2 based.