How to mount a 1959 fleetside bed with no wood

[Dave K]

I have a 1959 Fleetside and the bed wood is all rotted away and the bed seems to sit 1/2" or more lower then it should (judging by the way the body line on the bed lines up with the body line on the cab) It seems like the bed must have sat on wood blocks originally or some other spacer that is missing? What have people done to mount there beds when they don't want to run the stock wood?