LS364/450 Tech Specs:

• Balance: Internal
• Block: Cast iron with 6-bolt cross-bolted main caps
• Bore x Stroke: 4 in. x 3.622 in.
• Camshaft: LS6 Hydraulic roller
• Camshaft Duration: 204º intake / 218º exhaust (@0.050 in.)
• Compression Ratio: 10.3:1
• Connecting Rods: Powdered metal
• Crankshaft: Nodular iron
• Cylinder Heads: Cast aluminum LS3 rectangular port with 68cc combustion chambers
• Displacement: 364 ci  (6.0L)
• Engine Type: Performance LQ9 long block
• Fuel: 91-94 Octane (premium)
• Max Recommended RPM: 6,800
• Oil Pan: LQ9
• Pistons: Hypereutectic aluminum
• Reluctor Wheel: 24X
• Rocker Arms: Investment cast, roller bearing trunnion
• Rocker Arm Ratio: 1.7:1
• Valve Lift: 0.550 in. intake/0.550 in. exhaust
• Valve Size: 2.165 in. intake (hollow stem)/1.590 in. exhaust (solid stem) 

Installation Notes:

• This long-block engine assembly does not include an induction system, ignition system or accessory drive system 
• Compatible with GM Gen III engine controllers (sold separately, tune required)
• Compatible with LS3/L92-style rectangular port intakes (sold separately)
• Compatible with production LS3/L96 intake manifolds (sold separately) when using an aftermarket adapter plate for use with early GM LS three-bolt throttle bodies
• Not intended for marine use

Engine Break-In Procedure

Use only engine oil that meets dexos1 specifications. For track events or competitive driving, use Mobil 1 15W-50 engine oil. Fill the engine with oil and follow the proper engine priming procedure.  Also check and fill as required any other necessary fluids such as coolant, power steering fluid, etc.

Start the engine and listen for any unusual noises. If no unusual noises are noted, run the engine at approximately 1000 RPM until normal operating temperature is reached.  The engine should be driven at varying loads and conditions for the first 30 miles or one hour without wide open throttle (WOT) or sustained high RPM accelerations.  Run five or six medium throttle (50%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. Run two or three hard throttle (WOT 100%) accelerations to about 4000 RPM and back to idle (0% throttle) in gear. 

Change the engine oil and filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is functioning properly.  Drive the next 500 miles (12 to 15 engine hours) under normal conditions. Do not run the engine at its maximum-rated engine speed. Also, do not expose the engine to extended periods of high load.  Change the oil and filter again, inspect the oil and oil filter for any foreign particles to ensure that the engine is functioning properly.