Holes are 39.75" frame rail to frame rail.
Holes close to each other (middle and outside toward bumper) are 3.875" apart
Middle hole to furthest (inside toward axle) hole is 8.125" apart
It's 12" from the furthest (inside toward axle) hole to the outside (toward bumper) hole.
Hole diameter is 1/2", and they are oval for alignment purposes.