Cummins 4003994 Front/Rear Exhaust Manifold PAI 181018CROSS REFERENCE: 3067406 4003994 APPLICATION: Cummins L10 M11 ISM Series Multiple Use Application BRAND: PAI 181018 4003994 Front Rear Exhaust Manifold PAI 181018. Truck parts and diesel parts. Supports exhaust flow and stabilizes emission operation for dependable engine function. All components are proudly manufactured in the U. S. A. by PAI Industries Inc., an ISO9001 certified company with over 50 years of experience in the heavy duty truck parts