A bumper design question.

[Garrett.d.w]

Hi,
I have been looking to mount the rear bumpers on the bot. However, we have a series of bolts (two) that extend 3/4 of an in beyond the frame. As of now, I was considering drilling corresponding holes in the bumper backer, allowing the bumper to sit flush against the frame (with the bolt ends inside the bumper).

Would this be legal? I searched through Q/A as well as the rules and couldn't find anything relating to the topic. I do feel, however, that I might not get a response from Q/A (design review rather than a rule clarification).

I can answer clarifying questions, provide pics, etc.

Thanks