Corvette Performance - How much of a diifference between

My current rear end set up of 3.15 compared to a 3.42 gear set up? What kind of gains should i expect? How does the 3.15 set up compare to the fbody 3.23 set up? They are both supposed to be the performance option for A4s

The right locking converter would do a whole lot more. And still keep your rpm the same once locked. A 3.42 is a little too low gearing for an A4 if you do much freeway/highway driving IMO.

A 3,42 will be just fine on the highway even with the A4. Most people who swap gears put 3.73's in the A4 and either 3.73's or 4.10's in the M6. At highway speeds with the 3.42 you will prob notice a difference of about 200 rpms max.