Welcome to a brief series that charts the evolution and features of the modern GM small-block. This is part two—be sure to check out part one here, which includes a quick backstory and then hops into the details of the most ubiquitous V-8 engine family of the 21st century. Stay tuned for part three. —Ed.

Gen-IV: LS2 through LS9 and All Points Between

Engine: LS2

Displacement: 6.0L

Max Power/Torque: 400/400

Model Years: 2005-2009

Domestic Applications: 2005-2007 C6 Corvette, 2006-2007 CTS-V, 2006-2009 Chevrolet TrailBlazer SS/2008-2009 Saab 9-7X Aero, 2005-2006 Pontiac GTO, 2005-2006 Chevrolet SSR

The fourth-generation small-block hit the scene in 2005 as an evolution of the LS. It was the result of a two-pronged directive to increase displacement and incorporate gas-saving measures such as flex-fuel compatibility and displacement-on-demand (DOD) technology on an optional basis. The first member of this group, the 6.0-liter LS2, was rendered obsolete after just four years on sale, but it still managed to proliferate across GM’s portfolio more than any other LS or LT V8 in history. It made it into the C6 ‘Vette first with 400 HP, acted as a mid-cycle replacement for the LS1 in the GTO and the LS6 in the CTS-V, and even found its way into the engine bays of a truck (the throwback two-door convertible SSR), an SUV (Trailblazer SS), and even the Saab 9-7X Aero.

Engine: LS7

Displacement: 7.0L

Max Power/Torque: 505/481

Model Years: 2006-2015

Domestic Applications: 2006-2013 Corvette Z06, 2013 Corvette 427 Convertible, 2014-2015 Camaro Z/28

This is where the LS family cemented its place in history. At 427 cubic inches (the largest production small-block in Chevy history), the LS7 brought back a legendary displacement from the 1960s glory days and was the first small-block to crack 500 horses from the factory. With a lightweight aluminum block, unique pressed-in cylinder liners, forged titanium connecting rods, a forged steel crank and main bearing caps, and hypereutectic aluminum-alloy pistons, GM baked plenty of sophistication to its modern, large-bore brute. The LS7 was the first small-block to outmuscle its slithering cross-town V-10 rival since the C4 ZR-1 tapped out in ’95. It also put the C6 Z06 firmly in the same performance realm as pricy exotic contemporaries from Europe, such as the 512-horse Lamborghini Gallardo and 483-horse Ferrari F430, and was notable for its ability to rev to a healthy 7,000 RPM.

Engine: LS3

Displacement: 6.2L

Max Power/Torque: 436/428

Model Years: 2008-2017

Domestic Applications: 2008-2013 C6 Corvette, 2010-2013 C6 Corvette Grand Sport, 2009 Pontiac G8 GXP, 2010-2015 Camaro SS, 2014-2017 Chevrolet SS Sedan

With the LS7 unleashed and wreaking havoc on the upper reaches of the sports car market, Chevrolet turned its attention back to the base car. Starting with the LS2, engineers strengthened the casting and enlarged the bores to land at the magic 6.2 liters of displacement that’s still going strong at GM. The LS3 bumped the base ‘Vette by 30 ponies before the optional performance exhaust added another 6 for a total of 436. The following model year, an LS3 in 415 HP tune would power the G8 GXP that served as Pontiac’s curtain call. In 2010, a 426-horse version helped resurrect the Camaro SS that had been missing in action since 2002, while the Vette team paired the Z06’s wide body style with the LS3 to create the new Grand Sport that was so popular it unseated the base car as the range’s volume seller for the first time.

Engine: LSA

Displacement: 6.2L (Supercharged)

Max Power/Torque: 580/556

Model Years: 2009-2015

Domestic Applications: 2009-2014 Cadillac CTS-V Sedan, 2011-2014 CTS-V Wagon, 2011-2015 CTS-V Coupe, 2012-2015 Camaro ZL1

The Second-Generation Cadillac CTS-V was able to shoot past the once-untouchable stalwarts of the super sedan hierarchy with the infusion of the “ZR1-Lite” LSA V-8. In Cadillac guise, the LSA made 556 HP and 551 lb-ft of torque before being augmented to 580/556 in the Shelby-fighting fifth-gen Camaro ZL1. The primary difference between the LS9 and LSA was the latter’s smaller, 1.9-liter blower, but it also had slightly lower compression, wet sump oiling (vs. the LS9’s dry setup), cast pistons where the ZR1’s were forged, and half the intercooler heat exchangers (one in the V,-Series, two in the ZR1).

Engine: LS9

Displacement: 6.2L (Supercharged)

Max Power/Torque: 638/604

Model Years: 2009-2013

Domestic Applications: C6 Corvette ZR1

After the mighty LS7, the only way for GM engineers to extract more power from the Gen IV was to turn to forced induction, and they did exactly that in 2009. The greater of two closely-related engines spawned from this power-adding project was the LS9, GM’s crown jewel at the time. In a first for Corvette, Chevy fitted a supercharger—A 2.3-liter Eaton four-lobe Roots-style unit—to its venerable small-block. Rather than use the high-strung LS7, they settled on a 6.2-liter displacement that allowed for thicker cylinder walls and cast-iron cylinder liners. All told, the LS9 was strengthened by around 20 percent over prior aluminum small-blocks. Because of this attention to detail, the mod-happy owners have found that the stratospheric factory 638 HP starting point is exactly that: a starting point.