Are there any big advantages to switching out a 4g64 crank into a 4g63? Can someone tell me a few if there are any.

 

If you go w/ a 4g64 crank into 4g63 you'll go from a 2.0 to a 2.3. In doing this you'll also need pistons w/ a shorter compression height. The benefits from doing this is adding more displacement, torque and spooling time on the turbo.