BluePrint Builder Series LS427/625HP Standard Edition EFI Crate Engine and T56 Transmission Combos BLS427KT56

This version of BluePrint's LS427/625 combo keeps the polished front accessory drive and pairs the 625-horsepower, 427 cubic-inch engine with a 6-speed T56 manual instead of an automatic. Compression is 11.0:1, torque is 565 lb-ft, and the forged crankshaft and forged pistons are shared with the rest of the LS427 lineup.

Who this suits

This suits a builder who wants six manual gears and the polished look rather than the black-drive T56 version BluePrint also sells. An LT4-style drive-by-wire throttle body sits under an LS3-sourced intake manifold, with 42-pound injectors drawing from a return-less fuel rail, so the fuel and air side arrives tuned rather than needing separate sourcing.

What to check before ordering

Chevrolet built the 7.0L/427 LS engine this combo is based on between 2006 and 2015, so check that your application falls in that span. McLeod's Super Street Pro twin-disc clutch handles engagement, while a steel bellhousing and non-weighted billet flywheel complete the T56 package, geared with a 2.66:1 low first for launches. An oil pan built to fit most front-engine, rear-drive GM V8s from 1955-95 is included, and the combo is not suited to dry-sump oiling or emissions-controlled builds. BluePrint calls for 91-93 octane gas and BPP710 oil, and for accurate mass air flow readings points to its own air intake kit, the same one used on its dyno.

Common questions

Is a flywheel included? Yes, a non-weighted billet flywheel matched to the T56 clutch.

Does the ECU allow local tuning? Yes, BluePrint leaves it unlocked so a dyno shop can finalize the calibration.

What transmission does this pair with? A 6-speed T56 manual rather than an automatic.