[Fully Vetted]

The bottom line to me is you can only choose one gear. You have to figure out what your goal is and what sacrifices you're willing to make. Personally, I don't track my car. But, the stock gears are dogs on the street and I was tired of having to be just in the right gear all the time. The 3.90's still allow me to use first gear effectively while cruising while at the same time giving 3rd and 4th gear a ton more punch. I'm not saying 4.10's don't do the same but I have closed 80% of the gap between stock and 4.10's and I haven't given up anything. If you've done the mods and can pull a little taller gear I would say go with 3.90's or even 3.73's. I've always gone with the rule that for street cars the more power you have the taller gear you can pull.

BTW - there are plenty of threads about this very subject on this site and they all end the same. People have different uses for their Z and every one of them require a different gear set up.