Replacing seats on Pelican Gator????

Any you guys ever replace the seats in one of these? I wanted to add a 6"pedestal to raise the seats up. Well the holes or whatever is under the seat that accepted the original lag bolts is junk and wont hold the new bolts. I even threw some epoxy in the holes. Do any of you know whats under there? Wood? Should I just move the seats over a bit to try and grab some new wood? Any help or advise is appreciated Thanks