I have a 03 f350. I put a motor in it from asheville rebuilder. It keep hydro locking on cylinder 6. Had all 8 injectors tested and they were all good. My mechanic said head was bad on the driver side. Replaced head and start it up and then it hydro locked on cylinder numbed 1 and 3. I sent the driver head back to Asheville engine rebuilders and they said it had a crack. We pulled the passenger head off and working on getting it back together. I called asheville to see if they had tested the passenger side head. And he changed his story and said the driver head was not crack and that I had the wrong injector hold downs. Did ford have different hold downs and could hold downs cause the injector to hydro lock a cylinder thanks for any feed back