Dejavu2040

New to the forum. Figured this was the best possible place to find answers.

I have a 66 coupe and am in the process of replacing floor pans. My under floor supports are in need of replacement and they are pretty rusted and dented. I have leveled my car according to the diagram. When welding the supports in, should they be level (parallel to the datum line) or is there another set of measurements to the datum line I might be missing.

Any info is greatly appreciated!

Coupe

Install the one piece floor and then once it is sitting at the right depth on the rockers and sitting on the transition panel and the toe boards properly you can position those extensions so they hit the floor.