Just purchased a set of OEM step boards for my 1997 Wrangler. The bolt pattern is correct but the frame isn't threaded and no open hole on the inside of the frame to put a nut on a bolt. Am I totally over-looking something. The steps didn't come with bolts, but that's no problem if I can figure out how to install bolts. Do I have to tap threads into the frame?.. Tks, genemarsh:confused ??