Mack 104GC5203M Exhaust Manifold PAI 2056CROSS REFERENCE: 25099962 21010850 104GC5203AM 104GC5203M APPLICATION: Mack Aset Multiple Use Application. DETAILS: Front Rear Exhaust Manifold BRAND: PAI 2056 Mack 104GC5203M Exhaust Manifold PAI 2056. Diesel truck parts and commercial truck parts. Supports consistent exhaust distribution and stabilizes temperature control. All components are proudly manufactured in the U. S. A. by PAI Industries Inc., an ISO9001 certified company with over 50 years