I have had 4.11's and you could barely shift fast enough to keep up with them. Made driving around town like driving a tractor!

3.55's now and love them. I have a Keisler 5 speed so the first 4 gears are still steep and put a smile on your face everytime but the OD on the highway drops right down 2200 rpm @ 70

If you have a 8.5 I would go for the 3.42 as a best of both worlds gear and steeper if you are heavier footed!