shipped to the guy that SpecialtyZ and I use for installs. He has put together (about) half the total of 4.10s sold. A good number of folks have also had their diffs shipped to him (from around the country), and his results are consistently excellent. He has made up special shims, gauging, and do-dads to insure correct contact betwwen the ring and pinion gears (backlash and pinion depth), so you get a quiet (or near quite) differential set up. His name is Russ Sylvis, and his phone number is 805 527-4387. A possible source in your area would be Rob at Z Car Garage (I believe in the San Jose area). Feel free to call me or SpecialtyZ if you have any additional questions. Take care, Mark