Is there a difference in the 8.8 from our trucks and from mustangs and other fords? The reason that I am asking is that I have a 98 f150 4.6 5 speed with an 8.8 w/3.55 gears and am thinkin about going with either 3.90's or 4.11's. Just want some more loww-end grunt, before the blower swap. Also while I'm at it I may just swap our the entire rear for one with rear disc brakes (what all is envolved in this?).