My transit level is a david white that I bought at a pawn shop about 15 years ago. It won't tilt. For a while I built and installed iron fences and gates. I would do like you are talking about to make a slope in the fence and keep the pickets straight. I always use a benchmark as I tend to kick the legs of the level from time to time and sometimes have to move it for something in the way. You guys have given me some great ideas. Right now Gustava has dumped water here so is to muddy to mess with. When I clean the ditches out I will post some pictures. Thanks again big dan