I've been searching the heck out of the forums, but I was hoping to get a more specific answer form some of the guys who know this stuff way better than me. I got my 08 sport 4x4 4.0 auto 3.73geared about a month ago and I've already put 265/75/16 m/t's on it, which was a 2" diam. increase. From what I've read in the gearing posts I've found in searches, I'm wondering if Ford changed the trans gearing for the 08's. With these tires at around 70 in OD I'm just barely doing under 2100rpm, and the power sucks. on any kind of a hill on the highway, or to get any acceleration at all, it jumps right out of OD, back and forth etc. If 4.10's would put it just about where it was stock (which I thought was kinda mediocre acceleration anyhow), and still pretty low rpms overall, how radical of a jump is going to 4.56's? if I'm at 2000ish now @ 70 in OD, where would the rpms be with 4.56's? Thats actually my main question btw, because I know I would love the power lol
! I'm getting a bonus check this week, and the gears right after so any help deciding is HUGELY appreciated. I know some will say 4.10's, but 3.73 to 4.10 doesn't seem worth the dough to me, and btw, I probably will go with some 33's 40k down the road when these tires are done.
HUGE THANKS FOR YOUR OPINIONS