12. When junkyard scrounging, one difficult part to these engines is that block displacement identification can't be easily determined with the engine bolted to a transmission since the displacement casting is on the back of the engine. Here is "6.0L" cast into an aluminum block on the rear section of the block, so this means we are dealing with an LS2. If the casting were a 6.0, 4.8, or 5.3 in an iron block then it would be one of the truck engines, with the 6.0 being the most desirable for torque and performance. There is an aluminum block with 5.3L displacement from a Chevrolet TrailBlazer and Turnkey offers a 350hp version. An aluminum block with a 5.7 casting is either an LS1 or LS6, and a 7.0 casting in an aluminum block is the newer Gen IV LS7.