B4, MX4R Bearing, Gasket and Seal Kit | Standard Manual Transmission Mazda RX7, B2000 B4, MRX4R 4-Speed RWD Standard Manual Transmission Bearing, Gasket and Seal Kit. Aluminum Case, Rear Load, Diesel.1979-1980 Mazda RX7 1.1L1980-1984 Mazda B2000 2.0L Part #: BK137A Decrease Quantity: Increase Quantity: