Fitment and Product Information. Cylinder Head, Ultra 18®, CNC Competition Ported, 56cc CNC Chambers, Ti Retainers, Small Chevy, Each. Brandname: Trick Flow Part Number: TFS-3181T001-C01 Product Details. Trick Flow Ultra 18® 250 cylinder heads with 18 degree runners make serious horsepowerpower ideal for drag and high-rpm circle track racing. Right out of the box, these heads deliver higher airflow numbers than fully prepped 23 degree heads. Features include Trick Flows CNC-profiled combustion chambers and CNC Competition Ported runners with a premium high resolution surface finish for maximum flow and performance. Ultra 18 250 heads accept most current 18 degree intake manifolds, headers, and other components. They require the use of…