I hope to get around to repairing my floorboards (51 3104) soon. I've looked at the FAM I don't know how many times and still can't figure out what the frame to floor clearance should be. Can anyone enlighten me? Section 1, Sheets 1.07 and 1.08 show 11.88" to top of floor, but is 0 at the bottom the bottom of the frame or some other point? John