I'm considering a swap and was wondering how streetable these gears are. Would there be a big difference between these and 3.73s?

 

I runa 4.10s in my A4 I think they run good. I have no problems on the street with them at all

 

streetability is in the feel of the driver, if you will...

I have seen many guys running them in their a4, but it all depends on your goals and where you want your car to be...

I will probably getting 4.30's when I finally get around to doing my rear...

 

I'm running them and they're really not that much different than running 3.73's (I mean, for highway driving, streetability, etc.). BUT, if your car is running ~116 mph through the traps, you won't be able to do that in 3rd gear with stock height tires, or a ~6000 RPM redline. On the street you'll be ok, but if you want to track the car, you'll definitely want (or need) to get a set of maybe 28" tires for the back so you can run over ~120 mph in 3rd gear.

So, maybe 3.73's would be better for your car? Or, if your motor can handle it, bump your rev limiter up around ~6500, and slap on taller tires, and get 4.10's .