Beam

I'm putting in a Sabelt 3 point double detachable harness (there are eyebolts and clasps at the mounting points to allow for removal without a wrench-convenient for a daily driver) Anyway, I ran into a problem when I tried to put the harness eyebolt in the rear seat rail bolt-hole closest to the door. It doesn't fit. The backseat and centerline bolts are fine, but I can't see a good place to mount this one without drilling.
Any suggestions?