I've got a '97 ZJ and it's undoubtly the loudest vehicle I've ever owned. Not that it makes it undriveable but when you buy one used it does give concern.
I initially had mine to the dealer a number of times and it was always the same, sounds normal. I even drove a few others from used car lots just to hear that it sounded the same.
What finally put me at ease was when my neighbor pulled in with his "new to him" 2000 WJ. We went for ride and if I closed my eyes (I wasn't driving ) I would have thought I was in my '97.
Go drive a few used models like yours and you will probably hear the same noise.
'09 Wrangler Unlimited
'00 Cherokee, blue.
'90 4dr Montero RS, PIAA lights, Silver