I have an engine with an I.D. D15B(no number), but I had to take out an oil restrictor to run the Y8 head I put on it. Its turboed now and I want to do a mild engine build. My question is, how can I determine if this block is JDM or USDM to figure out which rods I currently have. I received the motor rebuilt with a rebuilt DX head on it, and have no history on it. So I dont know if someone put the oil restrictor in or what. Is there a magic number hidden somewhere, or an extra tab hangin off the side of the block or somethin crazy like that... how can I identify this thing???