what gear?

I have 3.73's in my Z now and I just aquiered another rear from a friend who went with a 12 bolt with 3.42's... which gear would be the best for my car on the juice?? Car is an A4.

I am leaning towards the 3.42's being the best but was wondering what you guy's might think or have to say about it..

Thanks!

Gary.

anyone have an Idea?

Time in sig with 3.42's. :D I could use a set of 3.73's as my trap RPM is a tad low, but the 3.42's are a nice all around gear.