I ran into the same problem in the early '90's when I had an '87 Wrangler with a 4.2. Neither Wix nor Fram (I wouldn't buy a Fram now anyway) would fit. I had to buy a filter made by Purolator or go to the dealership. Even though the number on the others say they would fit, they would not. If you will look, I would bet that the number listed on the Wix is the same as the number listed for a '91 or later. As far as how the oil filter adaptor is turned, I have a verticle filter on my '92 4.0 engine and it has the standard threads. It does't have anything to do with the question but here is a very interesting article on oil filters.
http://minimopar.knizefamily.net/oilfilters/index.html