Now, with 5.29's, it would be faster, but MPG would be worse and it'd be winding the engine out on the highway.

To be fair to the person asking the question, neither of these are really true. 4.88's and 35's would put the engine back to nearly stock RPM's, so they wouldn't be "winding out" any more than a stock setup. 5.29's would only increase RPM's by 5% - hardly significant under ~3500 rpm.

Both would also likely increase mileage in day-to-day, mixed driving. Numerically lower gears are not a guarantee of mileage - if they were, Toyota would run in the low-3's:1... to be equivelant on stock tires where Corey is on 35's. Gears not only make up for tire size, but added weight as well.

Regardless, with the SC and (likely) decreased weight of all of the 'glass, I'm sure he'll be MORE than happy. My SC'd/URD'd 3.4 w/ 5.29's and 37's is okay... always want more.

Brian K. Gallus
I have nothing important to say.