I received a Ford reman and have had nothing but problems with knock and other issues. Chasing knock counts and having to drive a certain way to get the AOR back to -.96 each day has been driving me crazy. 20k miles in I found I was pushing water, Head gasket failed (sorta) removing the head and looking at the head bolts shown the failure location was due to a poor install. The area in question had a head bolt that shown it had not been fully install as matching up to the other bolts. When cleaning the threads in the hole it had a stopping point and had to be worked on to go deeper. While out, ported the heads and cleaned them up and added ARP's to lock them down. Still had knock... fast forward. 5k later I found the true problem. Bad rod bearings... while I use some great oil, I feel this only made the problem take longer to show up. Bad rod bearings and they took out the crank. Just replaced it with a young junk yard motor, replaced all the timing stuff, oil pump, water pump, and all timing related parts including phasers and solenoids. Fresh start - on stock tune it's never shown knock. Will be rebuilding the other with updated parts and slide it back in when the time is right to put down some real numbers