This BoostDistrict  427 Cubic Inch longblock is designed for high performance, capable of handling 1500hp and 25psi of boost with ease. Perfect for turbo or supercharger setups, this affordable option is built to last and deliver maximum power. Trust our expertise and experience for your next power-adder engine needs. This engine is fully machined, blueprinted and dyno tested to ensure quality prior to shipping.    Engine Specifications:• HP: 650 (Naturally Aspirated)• TQ: 590 (Naturally Aspirated)• Block: Dart SHP LS Next Cast Iron• Bore/Stroke: 4.125″ x 4.000″• Displacement (cu.in): 427• Crankshaft: Dart Billet 4.000″ Stroke Internally Balanced 58 Tooth 6 Bolt• Rods: Manley H Tuff H Beams 4340 Forged 6.125″ ARP 2000 Bolts• Pistons: JE Ultra Dished 2618 Forged with Thermal Coating, Lateral Gas Ports, .200″ Pin• Compression Ratio: 10.2:1• Rings: JE Pro Seal with Carbon Steel Top Ring• Cylinder Heads: Frankenstein M311 72cc/273cc with Black Nitride Stainless Steel Severe Duty Valves, Titanium Retainers and PAC .700″ lift Springs• Head Fasteners: ARP Head Studs• Head Gaskets: Cometic MLX• Lifters: Johnson 2116LSR Link Bar• Rocker Arms: OE powdered metal 1.7 ratio with Trunnion Upgrade• Oil Pump: Melling 10295 Standard Volume High Pressure Recommended Components:• Oil- 20W50• Oil Filter: Wix• Fuel System – OE EFI System or Aftermarket• Intake – Stock Fuel Injected or Aftermarket• Balancer- SFI Internally Balanced• Flex plate/Flywheel- Stock Internally Balanced• Timing- Set to Factory Specifications Via PCM Module (Tune Required)• Spark Plug: NGK BR7• Tuning: Chassis dyno tune required• Firing Order- Stock• Fuel – 91+ Octane• Recommended Stall Converter- 2800+ based on application• Headers- 1 7/8”+ depending on application Notes: This engine is built to handle up to 25PSI of Boost from either a Turbo or Supercharger.