My Kristi manual says the KT-3 has an S70FS differential, which is supposedly the same guts as an OC-4, but possibly in a different case. The manual says the case capacity is 6 lbs of SAE 90 and the lubrication chart says to change with 4lbs. Either way, a gallon of oil equals 6-8lbs, so a gallon should do an OC-4. Yes/No?