You all may have seen these before, but here are the part numbers for the spider gears for the Isuzu trannys: 890-236-4360 and 800-463-0601. They are still available through Isuzu truck parts, although pricey they are new and hardened. They run about $100.00 each. I also found complete differentials at Mid west Transmission in Minnesota. Phone number 888-824-2012. Nice lady by the name of Connie fixed me up.