Glenn
I intend to document this a little better but for now:
My trailer is made by Venture so if yours is different these dimensions may be off:
The distance between the u bolts forward is 38 - 1/2", Rear is 42", u bolt to outside of frame forward is 13" and rear 11"
The bunks are 2X6 carpeted and if I flip them parallel to the road surface the vertical distance between trailer frame and bottom of the bunk is about 4 1/2 - 5 " at the front and 6 1/2 - 7" at the rear.
The length of the exposed ram (measured from end of cylinder to base of fitting on end of ram) when all the way up is 1 5/8" and all the way down is 13"
EDIT: When board is all the way up there is 8 1/2" from the "trailing" edge of the end tip of the foil to the top of the frame. (aft most point in the slot).
A couple of photos for reference.