I have a hijacker 5ver hitch I took out of my 96 GMC. I had to get new angle brackets to fit the 03 3500 DRW. Also got a bolt package with a fish wire. Question is, how do I tighten the bolts in the box frame?? They are standard 1/2" X 1 1/2" hardened bolts with threads all the way to the head, with locking nuts with nylon inserts. Is there another kind of bolt I can get to install this hitch, maybe a fluted bolt like lug bolts on a truck? Any help would be appreciated. Thanks