My 03 engine is stamped J30A4. I think the timing belt jumped and haven't dove in but thought replacing the motor would be easier. I bought a j30a from JDM and when I asked what version of J30A it was, the seller said he wasn't sure, that the japanese engines don't get marked with the additional identifier of 1/2/3/4. I'm told by the shadetrees the JDM motor is weaker and not to use it but I can't find any JDM engines with the "4". Any help is appreciated.