Can somebody PLEASE tell me where to find the Castrol Hypoy C gear oil? I've been to Schucks, Auto Zone, Baxster Auto, GI Joes, and some local auto parts place...no luck. Can I just use redline gear oil? I can find Valvoline gear oil everywhere, and even found Penzoil gear oil at another place, but NO Castrol. Please help me out...plan on changing it out tomorrow. Thanks guys!