Does anyone know a way to tell if the BLOCK is a JDM ITR block or a JDM GSR block? I know the head is easy, however without pulling the head and looking at the pistons is there a way to tell what motor it came out of. I was thinking the serial #'s but i cant find a site that will break it down for me... Im buying this motor used and just want to make sure i am getting what i am paying for...

 

edit: sorry wasnt thinking

i THINK the R blocks are 1,000,000 series numbers