BluePrint GM LS-Compatible Base Dressed Engine – 427 c.i. – 605 HP
PSLS42730CTF
605 HP · 565 lb-ft · 427 c.i. · 91+ Octane · Dyno Tested · 30-Month/50,000-Mile Warranty
Built for builders who want big-cubic-inch LS power without starting with a bare long block, this GM LS-compatible 427 cubic inch base dressed engine produces 605 horsepower and 565 lb-ft of torque. The 4.125-inch stroke delivers strong torque across the operating range, making this engine a solid choice for rock crawlers, rock bouncers, Ultra4 cars, trail rigs, muscle cars, hot rods, and custom trucks.
The engine is built around a high-strength LSX-style cast iron block with increased deck thickness, reinforced webbing, an extended cylinder skirt, priority main oiling, and six-bolt main caps. A forged steel crankshaft, forged 6.125-inch connecting rods, and forged pistons provide the rotating assembly strength needed for high-output applications.
This base dressed package includes the intake manifold, throttle body, fuel injectors, fuel rail, water pump, ignition coils, sensors, spark plugs, wires, oil pan, and harmonic balancer. It does not include an ECU, wiring harness, engine controller, flexplate, flywheel, or front accessory drive. Builders can select the engine management and accessory system that best fits the vehicle.
Need to confirm fitment or get an exact delivered price? Call or text our team before ordering.
Includes:
- GM LS-compatible 427 cubic inch assembled engine
- High-strength cast iron LSX-style block
- BluePrint LS3-style aluminum cylinder heads
- Hydraulic roller camshaft
- GM-style plastic LS3 intake manifold
- 42 lb/hr fuel injectors rated at 58 PSI
- Fuel rails
- Drive-by-wire throttle body
- Water pump
- Ignition coil packs
- Engine sensors
- Spark plugs and ignition wires
- LS swap oil pan
- Windage tray
- Oil pickup screen
- Non-weighted harmonic balancer
Note: This engine does NOT include an ECU, wiring harness, engine controller, flexplate, flywheel, starter, and front accessory drive..
Specifications
| Specification | Details |
|---|---|
| Engine Platform | GM LS-Compatible |
| Displacement | 427 Cubic Inches |
| Horsepower | 605 HP |
| Torque | 565 lb-ft |
| Compression Ratio | 11.0:1 |
| Block Material | High-Strength Cast Iron |
| Block Style | LSX-Style |
| Bore | 4.0685" |
| Stroke | 4.125" |
| Main Caps | 6-Bolt |
| Rear Main Seal | One-Piece |
| Crankshaft | Forged Steel |
| Connecting Rods | Forged 6.125" |
| Pistons | Forged, 22cc Dish |
| Engine Balance | Internally Balanced Front and Rear |
| Cylinder Heads | BluePrint PS8015 Aluminum |
| Combustion Chamber | 69cc |
| Intake Valve Size | 2.165" |
| Exhaust Valve Size | 1.590" |
| Intake Runner Volume | 259cc |
| Exhaust Runner Volume | 102cc |
| Camshaft Type | Hydraulic Roller, Three-Bolt |
| Camshaft Lift | .624" Intake / .624" Exhaust |
| Camshaft Duration @ .050" | 239° Intake / 255° Exhaust |
| Lobe Separation Angle | 114° |
| Intake Manifold | OEM-Style LS3 Plastic Intake |
| Throttle Body | Drive-by-Wire |
| Fuel Injectors | 42 lb/hr @ 58 PSI |
| Spark Plug | CCH9405 |
| Spark Plug Gap | .045" |
| Firing Order | 1-8-7-2-6-5-4-3 |
| Harmonic Balancer | Non-Weighted |
| Fuel Recommendation | 91+ Octane |
| Oil Capacity | 6 Quarts (with production oil pan and correct filter) |
| Recommended Stall Converter | 2200 RPM or Higher |
| Engine Management | Not Included |
Block Features
- High-strength LSX-style cast iron construction
- Increased deck thickness for improved cylinder sealing
- Reinforced block webbing for greater structural support
- Six-bolt main cap design
- Priority main oiling system
- Improved water jacket design
- Extended cylinder skirts for additional piston support
- One-piece rear main seal
- Accepts OEM-style LS3 front and rear covers
- Internally balanced rotating assembly
Important Installation Notes
Built by Off-Road People, Supported by Off-Road People
Wide Open Design has more than 20 years of experience building LS-powered rock crawlers, trail rigs, race cars, and custom tube-chassis vehicles. We can help you match the engine with the correct cooling system, fuel delivery, transmission, drivetrain, and installation components for your build.
- This engine does not include an ECU, wiring harness, or engine controller.
- A compatible drive-by-wire engine management system is required.
- A non-weighted flexplate or flywheel is required.
- Recommended flexplate or flywheel options include BPP12654640 and BPPLS1611.
- A 2200 RPM or higher stall converter is recommended for automatic transmission applications.
- Custom ECU programming and dyno tuning are required.
- BluePrint recommends air intake kit BPPLS01013 to help maintain proper MAF calculations and calibration.
- The retrofit oil pan is designed to fit many 1955-1995 GM front-engine, rear-wheel-drive V8 applications, but chassis clearance must be verified.
- Engine mounts, transmission adapters, cooling system, exhaust, fuel delivery, starter, and accessory drive components must be selected for the vehicle.
- Not intended for pollution-controlled vehicles.
- Not designed for dry-sump oiling systems.
Best For
Application: GM LS engine swap and performance applications
This is a universal performance engine intended for custom installation. Fitment depends on the engine mounts, oil pan clearance, transmission, transfer case, accessory drive, cooling system, exhaust, fuel system, wiring, and engine management selected for the build.
Common applications include rock crawlers, rock bouncers, Ultra4 cars, trail buggies, muscle cars, hot rods, classic trucks, custom 4x4 vehicles, and performance street builds.
Frequently Asked Questions
Is this a complete running engine?
No. This is a base dressed engine. It includes the intake manifold, throttle body, injectors, ignition components, water pump, oil pan, and harmonic balancer, but it does not include an ECU, wiring harness, engine controller, starter, flexplate, flywheel, or front accessory drive.
Does this engine include an ECU and wiring harness?
No. The engine does not include an ECU, wiring harness, or engine controller. The builder must select a compatible drive-by-wire engine management package.
What fuel does this engine require?
This engine requires 91-octane or higher gasoline.
Is the rotating assembly forged?
Yes. The engine uses a forged steel crankshaft, forged 6.125-inch connecting rods, and forged pistons.
What transmission can be used with this engine?
This engine can be paired with many GM-compatible automatic and manual transmissions when the correct bellhousing, converter, flexplate, flywheel, and control system are used. Common choices include the TH400, 4L80E, Powerglide, and Tremec manual transmissions.
What stall converter is recommended?
A stall converter rated at 2200 RPM or higher is recommended. Final converter selection should be based on vehicle weight, gearing, tire size, transmission, and intended use.
Is this engine a good choice for an off-road build?
Yes. The 427 cubic inch displacement and 565 lb-ft of torque make it well suited for heavy off-road vehicles, large tires, deep gearing, and technical terrain. Proper cooling, oil control, fuel delivery, and drivetrain selection are still critical.
Will the included oil pan fit every LS swap?
No. The included retrofit oil pan fits many GM front-engine, rear-wheel-drive applications, but clearance must be checked against the chassis, front axle, suspension links, steering components, and crossmembers.
Does this engine require custom tuning?
Yes. The ECU must be programmed for the engine combination, injectors, throttle body, intake system, transmission, and vehicle configuration.
Can this engine be used with a dry-sump system?
No. This engine is not intended for dry-sump applications.
