I've got an 02 f150 fx4 with 5.4l and Im about to put new trans and 35s. I wanna get some lower gears to make up for the bigger tires. Possibly go a little lower than originally. I've read around and seen a post saying 4.53 or close to that (not sure exact numbers) will work good with 35s. I dont go any faster than 75 so I wanna go as low as possible without revving up real high at that speed. Are those the gears I should go with? Was looking on ebay at some ford racing gears. Good brand? How do I tell what differential I have? I believe I have 8.8 with 31 spline in back and 28 up front?Can I install them myself or do I need a mechanic? I know thats alot of questions but Im very new to differentials. Never had a 4x4 before. If any of yall can answer any of these questions I appreciate it. Investing alot of money into my truck to catch up with my podna. Hes got a z71 that I've gotta out-do!