I believe my bed height is closer to 46" and when I load slowly by cable, I have about a 1/2 inch clearance. Picking your area for loading has the most effect on clearance, if needed, place a 2x6 under the bottom of your ramps and or that piece of angle iron at the hinge of the ramps.
I do get into the car and drive it off. Adds a couple hundred pounds, but doesn't touch bed.
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