572-cubic-inch V-8s, with most of the displacement gain coming from a stroke that's longer. To provide clearance for that long-stroke, engineers modified both the block and the connecting rods. Four-bolt main caps and a forged rotating assembly assure strength and durability. During development, a single-engine endured more than 200 simulated drag strip passes on a dynamometer. The ZZ632/1000 crate engine is slated to be on display at the 2021 SEMA Show in Las Vegas, November 2–5. Chevrolet Performance dealers will begin deliveries in early 2022. Generation VI Vortec 7400 (L29) The Vortec 7400 L29 V8 was a truck version of the Chevrolet Big-Block engine. Introduced in 1996, it was produced for five years, until replaced by the Vortec 8100. Although introduced as the Vortec 7400 in 1996, it was basically a 454 Big-Block with a hydraulic roller cam, parts more suitable for use in light duty trucks, and more advanced technology. The engine had MPFI (multi-port fuel injection), which gave slightly more power and better fuel economy, and 2 valves per cylinder. The engine had a bore and stroke of , producing at 4000 rpm and at 3200 rpm. L29 Applications: 1996–2000 Chevrolet/GMC C/K GMT-400 platform trucks 2500 and 3500 1996–1999 Chevrolet Suburban 2500/GMC Suburban 2500 (option) 1996–2000 Chevrolet Express 3/4 or 1 ton Vortec 7400 (L21) The Vortec 7400 L21 was a commercial version of the Chevrolet Big-Block engine used in the medium duty truck platform. Its design shared much with the L29 454, but with the addition of forged pistons and crankshaft, and coil near plug ignition. It had slightly reduced power compared to the L29 454 and used a different PCM. The L21 was paired with the early 4 speed Allison automatic transmission or manual transmission, depending on the application. L21 Applications: 1998–2001 Chevrolet Kodiak/GMC TopKick/Isuzu H-Series 4500 5500 1998–2001 Kodiak/Topkick 1998–2001 P12 HD Motorhome Chassis. The Workhorse W-20 is a clone of the P12 Chassis. Generation VII Vortec 8100 (L18) The Vortec 8100 L18 is a big-block V8 engine primarily used as a truck engine. It was a redesigned Chevrolet big-block engine and was introduced with the 2001 full-size pickup trucks. It is an all-iron engine (block and heads) with two valves per cylinder. It retained the same bore diameter as the old big-blocks, but the stroke was upped by to reach , for a total bore and stroke of . Power output ranged from ,