Description

This cylinder head is built for early-model Cummins ISB 24V engines and replaces OEM part number 3991773. Made from high-strength cast iron and precision-machined to OEM specifications, it ensures proper valve seating, combustion chamber sealing, and airflow. Ideal for medium-duty applications, this head offers thermal durability, long service life, and reliable performance in diesel-powered vehicles and equipment. Application: Aftermarket Cummins B Series ISB Notes: 24 Valves Bare Cylinder Head Non-Common Rail Style Key Features OEM replacement for Cummins 3991773 Fits early-model ISB 24V (5.9L) engines Precision-machined for accurate valve timing and airflow Durable cast iron for strength and heat resistance OEM-style fit for easy installation Compatibility Cummins ISB Early 24-Valve (5.9L) Engines OEM Replacement Part #: 3991773