4BT Cummins Manifolds

3.9L Cummins 4-Cylinder Manifold | 4BT Exhaust Upgrades

Diesel Power Source manifolds for the 3.9L Cummins 4-cylinder engine deliver strong airflow and reliability for industrial, off-road, and swap projects. Our precision-cast design improves boost control and turbo spool while resisting heat stress and cracking. Ideal for durable performance in compact diesel builds.