Use a stud instead of a bolt. I had the same issue with my two bolts at the rear (closest to firewall)....didn't feel like much thread was left after power plate was installed. I didn't want to chance stripping the threads.
Take the bolt with you down to Home Depot / Lowes etc, and match up the threads .....buy a short length of threaded rod (stainless or galvanized it doesn't really matter).....cut it slightly longer than bolt you're replacing... screw it in till it bottoms out....then install your nut.
Should be good to go!
dave