BluePrint PSLS4271CT Pro LS 427 625HP EFI Drop-In Base Crate Engine

Description

Harness responsive electronic fuel injection through the BluePrint PSLS4271CT Pro Series Crate Engine. Displacing 427 cubic inches, this 7.0 liter competition long block produces 625 horsepower at 6300 RPM and 565 lb-ft torque at 4800 RPM. Large rectangular port CNC cylinder heads and a race profile roller camshaft provide an exceptional foundation for custom street builds.

An aftermarket iron block casting provides structural stability across 4.125 inch bores and a 4.000 inch stroke. The reciprocating group combines a 4340 forged steel crankshaft, forged 6.125 inch H-beam connecting rods, and forged aluminum pistons yielding an 11.0:1 compression ratio. Operating on 93 octane pump gas, the six quart retrofit muscle car oil pan sets dry weight at 440 lbs.

Key Features of BluePrint PSLS4271CT

Buy BluePrint PSLS4271CT crate engine units to construct high revving pro touring racers, modern pickup restorations, and kit cars. The long block configuration provides a reliable rotating core ready for builder choice induction, fuel rails, or front accessory hardware.

• Large 4.125 inch cylinder bore diameter unshrouds intake valves for enhanced cylinder head flow.
• CNC ported rectangular port aluminum cylinder heads maximize air flow speed across oversized intake valves.
• Six bolt cross bolted iron main caps eliminate crank journal flex under elevated track RPM loads.
• Forged 4340 steel crankshaft withstands severe torsional loads during continuous high RPM operation.
• BluePrint PSLS4271CT valvetrain components feature upgraded dual valve springs to control valve bounce.
• Internal neutral balance crankshaft simplifies driveline balancing with standard modern flexplates.
• Multi layer steel head gaskets seal combustion spaces under severe operating heat and pressure.

Pro Series 427 Dyno Verification

Dyno tests confirm this small block generates 625 brake horsepower at 6300 RPM and 565 lb-ft torque at 4800 RPM across a wide 2500 to 6600 RPM operating band. Cam duration measures 238 degrees intake and 246 degrees exhaust at 0.050 inch lift, producing 0.620 inch intake and 0.620 inch exhaust lift. The engine draws 12 in-Hg vacuum at 900 RPM on 93 octane fuel, maintaining 50 to 65 PSI hot oil pressure.

Chassis Fitment Engine Mount Geometry

Standard GM LS architecture drops between subframe rails on vintage Camaro, Chevelle, and C10 chassis when paired with swap engine mount plates. The crankshaft accepts 4L60E, 4L80E, or manual transmission bellhousings using standard LS flexplates or flywheels. A retrofit muscle car oil pan clears front crossmembers and traditional steering center drag links.

Modern LS Priming Startup Guidelines

Technicians must pre prime the oil galleries using a pressurized oil tank connected to the block port before starting the engine. This modern LS long block is not engineered for marine bilge setups, forced induction boost exceeding six PSI on stock ring end gaps, or unmetered nitrous oxide systems.

• Drain break in lubricants and replace the spin on oil filter after the first 500 operating miles.
• Perform regular oil and filter changes every 3000 miles or six months with high zinc petroleum oil.
• Inspect valvetrain pushrod straightness and check spark plug deposits every 6000 street miles.

Documented Dyno Sheet Warranty Guarantee

Protection includes a 30-Month / 50,000-Mile factory limited warranty guarding against defective components. The shipment crate contains the assembled long block, aluminum cylinder heads, valve covers, timing cover, retrofit oil pan, harmonic balancer, comprehensive installation guide, and an official dynamometer run sheet.