I know this question has been asked before. I would like to know how to tell if my car has the LS6 or LS1 block. I know I have the 241 casting heads on the car but I know know how to tell which block it has. Can anyone help me out on this one??
Thanks!!

 

On the back of the motor, below where the head bolts to the block is the casting #. If the motor is still in the car you are going to need a mirror and a flash light. LS6 is 12561168. I just got an 02 motor and it's the ls6 block.

 

Is there any other place on the block and would be eaiser to read??

 

Nope that's the only spot. Use a small mirror that extends. Also ls1 blocks can have a dull or bright appearance to the aluminum, but all the ls6 blocks are of the dull grey like appearance. 10-15% of all 01s and 25% of all 02s have the ls6 block.

 

thanks for the info!!