Hey, I am doing my mini-me setup right now, but as I was rebuilding the bottom end in this 91 DX block (D15B2) I broke a chunk off a piston. The only thing that is available at this point in time is a 95 DX block (D15b7). The PM3 and PO3 pistons are said to be exactly the same but marked different for the newer OBD-1 block they came in. I need to get this running now, and that block is all I got. Do you think the piston is the same CR (compression ratio?) as the '91?? I need to know quick. They look almost exact but looks can be decieving.. Someone help me out while Im here.