LS1 or LS6 block. please help
LS1 or LS6 block. please help 
yep :) 
15% of 01s and 25% of 02's got the LS6 Block. The only way to tell 100% is to check the casting number. As you can see in the above pic (my ls6 block ) the casting number is at the top of the deck on the drivers side. Take a mirror and place it behind the block and check or jack up the car and attempt to look from the bottom. The "easier" ways are the casting hue and bulleye methods but none are conclusive. If you really want to know if you have the block you'll need to do the work and look for yourself, end of story.
Once you have determined if you have an LS6 block (ya you), then the only benefit to the block are the bay windows.
Its generally accepted from most engine builders that if your going for an extreme setup that the LS1 block offers more structural strength over the LS6 block.
some people said the LLS6 block increase some HPS looooooool no thats wrong its same LS1 block sooooooooo THE LS6 BLOCK DOES NOT INCREASE HP, REPEAT AFTER ME "IF I HAVE AN LS6 BLOCK IT DOES NOT INCREASE POWER". LEARN IT, SAY IT, REPEAT IT.
