Summit Racing™ Chevy LS 5.3L 450HP Long Block Crate Engines

Looking for big LS engine power at an affordable price? Summit Racing™ remanufactured 5.3L LS long block crate engines are rated at 450 HP and 420 lbs.-ft. torque! This engine will give you the performance and drivability you have been searching for at a price you can afford. It can be a performance upgrade for 99-07 Chevy trucks, or an engine swap into your project vehicle. You will save time and money by leaving the machine-work and assembly to us. Just bolt on your accessories and drop it in. These engines are machined and assembled for us by the guys at ATK, and backed with a 2-year unlimited mile warranty for peace of mind. Technical specifications: * Horsepower: 450+ * Torque: 420+ * Block: Seasoned OE LM7/5.3L iron * Bore/stroke: 3.800-3.820 in. x 3.622 in. * Year range: 1999-2007 * Displacement: 323 C.I.D. * Crankshaft: OEM GM 3.622 in. stroke internally balanced 24-tooth reluctor wheel * Connecting Rods: OE GM forged powder metal 6.093 in. * Pistons: Hypereutectic flat top * Piston rings: Moly * Compression ratio: 10:1 compression * Camshaft: Summit Racing Pro LS Roller * Camshaft specifications: Lift- 550/550, Duration @.050- 222/232 * Camshaft bearings: Installed and clocked to OEM position * Cylinder heads: #799 or #243 OE aluminum 64cc 2.00 in./1.55 in. valves * Freeze plugs: Brass installed and sealed * Rocker arms: OE powdered metal 1.7 ratio * Oil Galley plugs: Installed and sealed Show Less