....simple distance from the front of each plate would be good enough.
Paul.
What model D4? I have a 7J and a 7 U that I could try to measure for you.
Those floor plates are flat - no bends. (7U D 4's: 7U40602 and 7U40431)
they do have a slight bend well my 6u does.
Just checked D47U 36,475 no bends, and early model D4s appear to be the same, D2s have bends on the ends.