Crankshafts
Generally, LS crankshafts are similar in design, with identical 2.10-inch rod and 2.65-inch main journal sizes and a common rear main seal. All LS engines uses iron crankshafts except the LS7, LS9 and LSA; they used forged steel cranks (4.00-inch stroke on the LS7; 3.62-inch stroke on the LS9 and LSA).

The crankshaft sensing function of the distributorless ignition system depends on reading the toothed reluctor wheel on the crankshaft. Early LS engines mostly used 24-tooth wheels and upgraded a few years ago to 58-tooth (also known as 58X) wheels. When building an LS engine, it is imperative the correct reluctor wheel is used with the compatible crankshaft position sensor and ignition controller.

The crankshafts are mostly interchangeable, but the snouts on LS7 and LS9 crankshafts are approximately 1-inch longer to accommodate their two-stage oil pumps that work with the engines' dry-sump oiling systems. These forged crankshafts can be used on wet-sump engines by using a few specific components and/or modifications.

The easiest way to put a forged stroker crankshaft in your LS engine is using GM Performance Parts' new LSX crankshafts, which are available in four stroke sizes up to 4.125 inches. They feature the standard-length snout and can be used without modification on most engines. LS7 and LS9 crankshafts can be used, but require special components and/or modifications to their snouts to accommodate standard, wet-sump oiling systems.

Connecting Rods
LS connecting rods are very similar and interchangeable. Most are made of powdered metal, while the LS7 and LS9 rods are forged titanium. Rods lengths are similar, too, at 6.098-inch for 5.3L, 5.7L, 6.0L and 6.2L engines. The 4.8L engine uses 6.275-inch rods and the LS7 uses 6.067-inch rods. Since 2006, LS rods use bushed small ends. Also, LS6 rods bolts, P/N 11600158, offer a strength-enhancing upgrade to pre-2000 engines. Finally, because of the pistons' inner bracing, non-LS7 rods will not work with LS7 pistons; and the LS7 rods have a slightly different size than other LS rods, requiring a unique bearing, P/N 89017573.

LS7
A legend in its own time. The LS7 is the standard engine in the Corvette Z06 and its 7.0L displacement (427 cubic inches) makes it the largest LS engine offered in a production car. Unlike LS1/LS6, LS2 and LS3 engines, the LS7 uses a Siamese-bore cylinder block design - required for its big, 4.125-inch bores. Competition-proven heads and lightweight components, such as titanium rods and intake valves, make the LS7 a street-tuned racing engine, with 505 horsepower. LS7 engines are built by hand at the GM Performance Build Center in Wixom, Mich.

LS9
The most powerful production engine ever from GM, the LS9 is the 6.2L supercharged and charge-cooled engine of the Corvette ZR1. It is rated at an astonishing 638 horsepower. The LS9 uses the strengthened 6.2L block with stronger, roto-cast cylinder heads and a sixth-generation 2.3L Roots-type supercharger. Like the LS7, it uses a dry-sump oiling system. It is the ultimate production LS engine. It is built by hand at the GM Performance Build Center in Wixom, Mich.

LSA
A detuned version of the LS9, this supercharged 6.2L engine is standard in the 2009 Cadillac CTS-V. It is built with several differences, when compared to the LS9, including hypereutectic pistons vs. the LS9's forged pistons; and a smaller, 1.9L supercharger. The LSA also has a different charge-cooler design on top of the supercharger. Horsepower is rated at 556 in the super-quick Caddy.