The LS1 shares little other than similar displacement, external dimensions, and rod bearings, with its predecessor. It is an all-aluminum 5.7 L (5,665 cc/345.7 cu in) pushrod engine and was rated between 305 - 350 hp (227 to 261 kW) and 335-375 ft·lbf (454-508 N·m) of torque in North America, depending on the application. In Australia, continuous modifications were made to the LS1 engine throughout its lifetime, reaching 382 hp (285 kW) in the HSV's YII series and a Callaway modified version, named C4B, was fitted to HSV GTS models producing 402 hp (300 kW).

The version fitted to the 2004 Pontiac GTO was rated at 350 hp (261 kW) and 365 ft·lbf (494 Nm) of torque. Beginning in 2001, the LS1 received the higher-flowing intake from the LS6 and a milder camshaft to keep power at the same level; this also allowed GM to remove the exhaust gas recirculation (EGR) system (Camaro/Firebird only; 97-00 Corvette LS1 never used an EGR system). The block is very similar to that of the higher-output LS6; beginning in 2002, some LS1 engines were actually built using the LS6 block instead.[citation needed] The LS1 was on the Ward's 10 Best Engines list for 1998.

* 1997-2004 Chevrolet Corvette C5, excluding Z06
* 1998-2002 Chevrolet Camaro Z28, SS
* 1998-2002 Pontiac Firebird Formula, Trans Am, Trans Am WS6
* 2004 Pontiac GTO
* 1999-2005 Holden Commodore Ute
* 1999-2005 Holden Commodore (VT, VX, VY, VZ)
* 1999-2005 Holden Statesman (WH, WK, WL)
* 1999-2005 Holden Caprice (WH, WK, WL)
* 1999-2004 Holden Special Vehicles (all V8 models)
* 2001-2005 Holden Monaro CV8
* 2006-2007 Elfin MS8 Streamliner