The McCormick 6731201A1 is a genuine OEM engine block designed for various McCormick X-series agricultural tractors. This critical component ensures the structural integrity and proper functioning of the engine, providing a reliable foundation for internal engine parts. Confirmed fitment for McCormick X4.30, X4.40, X4.50, X4.60, X4.70, X4.80, X4.90, X5.20, X5.30, X5.40, X5.50, X5.60, X5.70, X5.80, X5.90, X6.420, X6.430, X6.440, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, X7.690, X8.660, X8.670, X8.680, and X8.690 tractor models.