I seriously doubt you have a FF 44. If you can't tell from the diff ID, look for two numbers on the BOM that would probably be the ring count and the pinion count. If you can't find that, you can do it the ghetto way and put the t-case in neutral, jack up the rear, and count the number of rotations of the driveshaft it takes the make one revolution with the tire and make an educated guess from that. OR you could pull the cover and count the teeth and the divide the ring by the pinion count. Most likely its something like a 3.08 or 3.42.... nothing too terribly deep; you'd probably be looking to regear.