So Far the suggestions have been to measure from the back of the front sub frame to the rear of the back frame and also from the center of the tires on each side.

I think with a couple of plum bobs I could get some of the other measurements but the diagram shows taking the measurment from the center of the hole on the frame. Since I have a bushing there and would not be able to find the center I would have to pick a different refrence point.