The plenum could just be JDM? I bought a JDM engine while I rebuilt my engine and drove the heck out of that JDM engine, overboosting and all, as I was replacing the turbos too. That engine was rock solid!!!! A friend bought it from me after I put my new engine in. He never had a problem. JDM does not mean it is bad. Just really hard to clean the goop out of it before running it.