OLDS 455 72-76 CYL HEAD

The ATK HP103 (With MDS) Gen III 5.7L Hemi Crate Engine is a high-performance replacement engine producing 400HP and 400TQ. It features a bored Gen III Hemi block, OE cast crankshaft and rods, hypereutectic 9.6:1 compression pistons with moly rings, and a Comp Cams hydraulic roller camshaft (216/220 @50 .528/.531 113LSA). The engine is equipped with OE Hemi 85cc/161cc 2.00/1.50 OHV cylinder heads and OE shaft mount rocker arms. It requires conventional/non-synthetic 5W/20 oil, Wix or K&N oil filter, and a computer ECM tune. Spark plug gap should be .035” and 91+ octane fuel is recommended. This engine is designed for car and truck applications with MDS (Multi-Displacement System) and features power steering holes in the front of the heads. It provides over 47HP+ gains compared to factory ratings, with strong mid-range power. A complete check of the fuel system is highly recommended to prevent fueling issues not covered under warranty.