Sales people I spoke to said the Bilsteins would be the last shock I ever bought for that vehicle. The OE shocks on my 2001 Chevy Trail lite were pretty well gone at 26K. Around town the Bilstein seem fine but I have not done any road traveling with them yet.
The gear vendors site is interesting but it would take a lot of miles at very improved mpg to make up $3200 plus $750 installation. On the otherhand, I don't know what replacing a 4:10 RATIO with a 3:73 would cost nor if there would be significant mpg change.
Surely, that kind of technical information is readily availabe to auto tech/engineer groups.