IRN 180/72 ST 2.05/1.60/1.250

The Dart 10221121 is likely an assembled aluminum cylinder head, designed for high-performance applications. While specific details for this exact MPN are unavailable, related Dart products (e.g., MPN 301-11021122 "Dart Pro1 LS1 Aluminum Cylinder Head [Assembled]") feature 225cc intake ports, 62cc combustion chambers, 2.050" intake valves, and 1.600" exhaust valves. These heads are typically made of aluminum with a natural finish, include manganese bronze valve guides, powdered metal valve seats, and positive stop valve stem seals. Emissions restrictions may apply, often making them legal only for non-emissions controlled vehicles or racing.