Generation III: The Vortec 5300, or LM7/L59/LM4/L33, is a V8 truck engine. It is a stroked (by 9 mm) version of the Vortec 4800 and replaced the 5700 L31. L59 denoted a flexible fuel version of the standard fuel LM7 engine.
Power output is 270-305 hp (201-227 kW) and torque is 315 lb·ft (427 N·m) to 335 lb·ft (454 N·m). Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 96.01 mm 3.78-inch (96 mm) bore and 92.00 mm (3.6 in) stroke 3.622-inch (92.0 mm) stroke .
The LM7 (VIN code 8th digit "T") Vortec 5300 was introduced in 1999, and can be considered the "garden variety" version of the Generation III 5.3 liter V8's. The LM7 has an iron block and aluminum heads.