Hmm, checked his site and he lists one part for all (presumably) XJ's 84-2001. Not my product but IMHO you really couldn't design one skid for BOTH 97- and 97+ tanks. So....call him back and see that you got the right one or if he even makes one for the 97+ ?
The skid doesn't even fit over the tank - which leaves it about 3 inches from the frame rail where it is supposed to bolt up. The skid isn't deep enough nor is it long enough as I can get the front in the right place (no hangars - 97+ use straps and the cut outs in the skid line-up with the straps) but the rear is about an inch to short and the bottom is pressed against the tank.