Here are a few pics from today. When I get a chance next week I'll try to get the rest in a photobucket link. Bob, a height of 40" to the top of the rail is used. Since the floor surfaces of the different buildings vary in how level they are, all the modules have a build in adjustment in the bottom of the legs. A bolt approx, 2" long and a t-nut is used for this adjustment. So yes, end to end, and front to back hight, and level, is important to ensure that the trains will run well. Gary, I'll see what I can do about a video as I don't have a camcorder, if need be I'll find a good link from youtube.