For the LS2, just do what I did, and buy a case of UPF44s from a forum vendor, like Gene.

Someone mentioned Maserati - I was just under a couple of Quattroportes last week for a legal assignment and the brand of oil filter on both of them was . . . . . . Maserati. Why publish specs when you can just sell your own brand of filter . . . made by . . . who knows ?