they didn't use the 8.25 until later. That one is kind of circular too. One way that works for me when trying to tell the Dana 35 from the 44 is that, in almost every case, the drain plug is metal with a square hole, like in the back of a socket. You actually put a rachet or extension into it and take it off that way. The 35 has a round rubber cap that you just pry off with a screwdriver. The 44 has a bit more of a buldge in the cap too, compared to the 35.