The Cummins ISB Hardened Pulley is a reliable and practical product designed to enhance the performance of your Cummins ISB engine. With OEM Pump Numbers 3286278, R4723690, 3285410, and 3285414, and an OEM Casting Number of 3920310, this pulley is compatible with most Cummins ISB makes and models. Its hardened construction ensures durability and longevity, making it a cost-effective choice for your engine. Upgrade your Cummins ISB with this high-quality pulley for improved efficiency and reliability.