The McCormick 1420559M91 Cylinder Head is an authentic OEM replacement component designed for McCormick MC series agricultural tractors. This essential engine part is crucial for proper combustion and valve operation, contributing to the engine's peak performance and efficiency. It is compatible with McCormick MC100, MC105, MC110, MC115, MC120, MC130, and MC135 models. This part number is superseded by 1420559M92, indicating an updated or equivalent replacement.