My alternator is not working and I need a replacement. However, when I go to all the autopart stores the alternator they give me does not match what I pulled from my 1990 4.2L Jeep Wrangler. They seem to be the same design in general, but the holes for the bolts are in the wrong places (they are turned 180 degrees). Also, mine has 5 grooves in the pulley and what they give me is a single groove. I just bought the jeep a month ago and I don't know if the alternator is stock or perhaps it's from another year Jeep. Any help would be appreciated. I included pics of what it looks like.