What are the main differences in the ls1, the ls2, and the ls6? what are the factory HP ratings, and there dispalcement sise, I know the ls1 is a 5.7, and the ls2 is a 6.0, but what are the ls6's? and what cars did they come in? also is the truck 6.0 block the same as the ls2 block other than being cast iron? like can you put ls2 internals + heads on the 6.0 iron truck block? if so wouldent it have close to the same hp rating?