Chassis Building 101. Ride Height

[Tincup]

I'm getting ready to start modifying my truck chassis and have a basic question. When you set up the bare chassis, you set it level, and at desired ride height, either on the shop floor or frame table. Do you actually set it at desired ride height or do you add a couple inches to account for when all the weight is put back on the chassis? I would think if I have a bare chassis, and I want a 6" ride height under the main rails, I should set it at say 8" so when everything is back together ( all the weight back on it ) it will be at my desired 6". I am running all coilovers so I will have some adjustment. Any help is appreciated...