If your new rig does not have leveling gauges (the ones with the bubble), buy two. They are cheap and generally mount with simple peel and stick tape. You want one reading fore and aft and one across the back (side to side). Always try to be with in one or 2 degrees of level both ways and you should have no problem operating your refrigeration. As soon as I pull/back into a site the first thing I do is check the bubbles and use the appropriate number of lego blocks to achieve the desired effect. :C