A bumper design question.

[Alan Anderson]

"Pocketing" the bumper backing to accommodate minor protrusions beyond the frame perimeter is okay. However, <R02> says such protrusions cannot be more than 1/4 inch. Your bolt heads go beyond that, so they'll end up defining the perimeter.

If you can't move the bolts, I think a good option at this point is to add a 1/2"-thick "shim" to the side of the frame where those bolt heads are. It'll add an inch to your perimeter measurement, though.