Transformative driving improvement with respect to putting the power down in longish corners.

OS Giken differential with BMW OE 4.44 gears.
Excellent condition with less than 6 events on the hardware.
Ready to go (with your rear cover).
Your 6spd M3 will pull hard in any corner/sweeper with immediate response.
New cost over $5,000.

Price $3600 picked up in/around West Chester, PA
Shipping possible, but on your dime.
PM with any questions.