The guys at Lorenzo’s Fast Flow Cylinder Heads in the Philadelphia suburbs have been in the engine game for a long time; owner Lorenzo D’Amore has worked on many of the area’s quickest and fastest engines and cut his teeth working for longtime area engine builder and speedshop owner Frank Bash Jr. before striking out on his own some years ago.

The shop, led by engine builder Jeff Prehl, recently put together this sweet 582 cubic inch, all-aluminum big-block Chevrolet engine for a customer who was looking for big power from a tame-looking platform. Using a standard-deck-height Dart block, a Callies 4.375-inch stroke Magnum forged crankshaft, Manley H-beam connecting rods, and a set of 4.600-inch bore Manley forged pistons, the engine is designed to produce 11.0:1 compression – perfect for a street engine running on pump fuel.

Also included in the build was a set of Dart Pro 1 345cc cylinder heads with one of the company’s custom valve jobs; the bowls were blended to the valvejob to clean up the port entry and exit..

Underneath the stock style stamped steel valve covers, valvetrain consists of a full complement of COMP Cams gear; short travel hydraulic roller lifters, a hydraulic street roller camshaft, and a set of Ultra Pro Magnum rocker arms. Camshaft specifications are mild for a big-block making this kind of power; .661/.661-inch lift and 251/259 degrees of duration at .050-inch lift. To create a broad torque curve, a 114-degree lobe separation was used on the core.

Continuing the stock-appearing theme, the decision was made to use a dual-plane GM manifold, which was shipped out to Wilson Manifolds to be completely ported. Extensive internal work was performed over dozens of hours to ensure the intake’s performance would be up to snuff when the engine was at full song.

With a Quick Fuel Technology 950 cfm carburetor on top, the engine blasted the shop’s dyno to 749 horsepower at 6,000 RPM and 743 lb-ft of torque at 4,800 RPM.

The engine is destined for use in a 1969 Corvette and will be backed up by a six-speed manual transmission. With big, street friendly low-RPM power like this on tap, we’d have to say that the owner will have his hands full in every gear. Sweet engine!