Is a body bushing the same as a body mount? Are runners same as cruisers? If yes, yes, you'll probably have to cut it off. Or maybe just torque it so hard that the head twists off. When I removed the body mounts on my 76 FJ40, some heads twisted off, some I cut off, and couple actually came out by undoing them...amazing!
If space is tight, the dremel's probably your best bet. If the bumper's in the way, how hard would it be to take the bumper off? You may consider torching as a last resort, the burning rubber smells really bad :-(