specs at .050 lift are: 190/191 duration, .466/.457 lift, 114 LSA, 112/116 Timing Applications: L59 The Vortec 5300 L59 (VIN code "Z") is a flexible fuel version of the LM7. The 2002–2003 made and , while the 2004–2007 L59s made and . Applications: LM4 The Vortec 5300 LM4 (VIN code "P") is an aluminum block version of the LM7, and had a short production life, as did the specific vehicles in which LM4s are found. LM4s made and , It should not be confused with the L33 described below. Applications: L33 The Vortec 5300 L33 (VIN code "B") is an aluminum block version of the LM7, marketed as the Vortec 5300 HO. Instead of the LM7's dished pistons, the L33 uses the 4.8L's flat top pistons. It also uses 799 cylinder heads, identical to 243 castings found on LS6s and LS2s, lacking only the LS6-spec valve springs and hollow stem exhaust valves. This combination raised the compression from 9.5:1 to 10.0:1. The L33 also used a unique camshaft not shared with any other engine, specs at .050 duration are: 193 duration, .482 lift, 116 LSA. As a result, power increased by , to and 335 lb·ft (441 N·m). It was only available on extended cab short bed 4WD pickup trucks. Only 25% of 2005-made pickup trucks had an L33 engine. Applications: 4.00 in. bore blocks (1999–2007) The 6.0 L is a larger version of the LS motor. 6.0 L blocks were cast of iron, designed to bridge the gap between the new small blocks and big blocks in truck applications. There were two versions of this engine: LQ4, and LQ9, the latter being more performance oriented. 6.0 L The Vortec 6000 is a V8 truck engine. Displacement is from a bore and stroke of . It is an iron/aluminum (1999 & 2000 model year engines had cast iron heads) design and produces and . LQ4 The Vortec 6000 LQ4 (VIN code "U") is a V8 truck engine. Displacement is from a bore and stroke of . It is an iron/aluminum (1999 & 2000 model year engines had cast iron heads) design and produces and . LQ4s are built in Romulus, Michigan and Silao, Mexico. Applications: LQ9 The Vortec HO 6000 or VortecMAX (VIN code "N") is a special high-output version of the Vortec 6000 V8 truck engine originally designed for Cadillac in 2002. This engine was renamed as the VortecMAX