This is how I chopped my top and got the rear window to come out real even. First I made sure the car was level. Then I took a piece of steel the same height as my chop (3") and made sure it was square. (see picture) Then I placed a small carpenters level on top of the steel and held it up against the side of the rear window.(see picture) At this point I marked the body at the top and bottom of the steel, and repeated on the other side. In doing this with a level, the distance from one side to the other, at both the top and the bottom will be the same, so when the top is lowered there is a lot less metal work to do at those seams. (The second picture was taken after the chop, because I forgot to take one as I was doing it.)
Well, that certainly makes sense, but I don't believe that I would have thought of it. Thanks for posting. Rich
God idea! We just chopped a F1 truck..to get the windshield the same on both sides we just got one side right and the other side close,made a cardboard template of one half of the windshield from an old beer box and used it to make sure both sides matched....as a bonus we got to empty the beer box first!