I'll dig into them further. The installation manual starts with sighting the four posts from a survey tripod base, didn't have that and knew if I set that up that the two posts where the drive on end is will be lower. I think I'm going to wait until both ramps are mounted then see what adjustments get it to, then bounce that against the spec. All the manual is talking about so far is if you are going to bolt the lift to the floor they mention shimming then. I bought the caster kit and don't plan on bolting it down.