When we were building/repairing round track race car frames, we used square tubing fixtures with caster wheels on them to roll unfinished projects around the shop. One bay was set up with chain anchors in the floor and jackscrew-type stands to support the frame, and the level floor was used as a surface plate baseline for all the measurements. We would chain the frame down level, and use a laser construction level on a tripod for precision height measurements. Places like Harbor Freight or Northern Tool have those lasers at bargain prices.
Jerry
