@Mcrews:
Yep, it's an LSC.
I have considered swapping to a 3.08 or 2.73 rear gear but I think that as much as it may help my highway mpg, it would hurt my city mpg. Not 100% sure, but it's definitely something I'll keep in mind.
I crunched some numbers last night at work:
O.E. tire = 225/60-16 (83.66" circumference)
first l.r.r. tire I found was 215/65-16 (84.83" circumference)
If I stick with the AOD gearset I'll have 2.40 1st, 1.47 2nd, 1.00 3rd and 67 O.D.
With my o.e. tires that would be 1,651 rpm at 55 mph and 2,101 rpm at 70 mph
With the l.r.r. tires it would be 1,628 rpm at 55 mph and 2,072 rpm at 70 mph.
If I use a 4R70W gearset I'll have 2.84 1st, 1.55 2nd, 1.00 3rd and .70 O.D.
o.e. tires = 1,725 rpm at 55 mph and 2,195 at 70 mph
l.r.r. tires = 1,701 rpm at 55 mph and 2,165 rpm at 70 mph
^with 3.55 gears.
I'm leaning toward the 4R70W gears since the deeper first gear would make it easier to get the car moving, at just under two tons it has a lot of inertia!
Hey, you made it to within 2 mpg of my goal with no mods! Maybe there is hope!
