II engines. The LS engine also used coil-near-plug style ignition to replace the distributor setup of all previous small-block based engines. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design (much like the 64-90 Oldsmobile V8), and the pistons are of the flat-topped variety (in the LS1, LS2, LS3, LS6, LS7, LQ9, and L33), while all other variants, including the new LS9 and LQ4 truck engine, received a dished version of the GM hypereutectic piston. The cylinder firing order was changed to 1-8-7-2-6-5-4-3 so that the LS series now corresponds to the firing pattern of other modern V8 engines (for example the Ford Modular V8). 3.898 in. bore blocks (1997–2005) The first of the Generation IIIs, the LS1 was the progenitor of the new architecture design that would transform the entire V8 line and influence the last of the Big Blocks. 5.7L The Generation III 5.7L (LS1 and LS6) engines share little other than similar displacement, external dimensions, and rod bearings, with its predecessor (LT1). It is an all-aluminum pushrod engine with a bore and a stroke of . LS1 When introduced in the 1997 Corvette the LS1 was rated at at 5,600 rpm and at 4,400 rpm. After improvements to the intake and exhaust manifolds in 2001 the rating improved to and ( for Manual Transmission Corvettes . The LS1 was used in the Corvette from 97 to 04. It was also used in 98-02 GM F-Body (Camaro & Firebird) cars with a rating of over , which was rumored to be conservative. The extra horsepower was claimed to come from the intake ram-air effect available in the SS and WS6 models. In Australia, continuous modifications were made to the LS1 engine throughout its lifetime, reaching 362 hp/350 ft-lb in the HSV's YII series, and a Callaway modified version named "C4B" was fitted to HSV GTS models producing and of torque. Applications: LS6 The LS6 is a higher-output version of GM's LS1 engine and retains the same capacity. The initial 2001 LS6 produced and , but the engine was modified for 2002 through 2004 to produce and of torque. The LS6 was originally only used in the high-performance C5 Corvette Z06 model, with the Cadillac CTS V-Series getting the engine later. The V-Series used the LS6 for two years before being replaced by the LS2 in 2006. For 2006, the Z06 replaced the LS6