[Big Dave]

If you know somebody that makes conveyor belt for a living, he will have a 15 ton press and some round dies. Much, much easier than drilling and looks nicer, too.

I didn't do any fancy fab. Made a template. Drilled the bumper and welded nuts on the back. Use SS fender washers and capscrews, and tighten then down death for tight.

My dam clears grade by seven inches in front of tires and ten inches above grade between the suspension. Less and she drags - particularly when braking.