BluePrint BP38350CT1 383 Crate Engine, 96-00 GM Vortec Truck/SUV

Built specifically to replace the factory 350 in a 1996-2000 GM Vortec truck or SUV, this 383 longblock drops in without ECU tuning or recalibration, and BluePrint rates it for a 47 rear-wheel-horsepower and 55 rear-wheel pound-foot gain over the stock engine, measured on a chassis dyno with the factory EFI and ECU left in place.

Why it bolts in without a tune

The camshaft here is milder than BluePrint's other 383 builds, specced at 202 degrees of intake duration and 212 degrees of exhaust duration, which keeps the factory computer happy without needing a recalibration. Aluminum heads, a hydraulic roller cam, a cast steel crankshaft, and hypereutectic pistons make up the rest of the architecture, built on a new cast iron block that uses four bolts on each main cap, with the rear of the crank sealed in BluePrint's one-piece style.

Legal status and fit

This engine carries California Air Resources Board Executive Order D-824-1, which covers legal installation in a qualifying GM pickup or SUV, model year 2000 or older, that originally came equipped with a California-certified, naturally aspirated 5.7-liter engine. BluePrint notes that reusing the factory front accessory drive can call for some bracket work on your end, since this swap wasn't designed around every stock mount. No carburetor, intake manifold, or distributor ships with it, since the vehicle's own EFI and ECU handle that job. Coverage runs for 30 months or 50,000 miles.