My 4.6 have 106k on it with a bad valve. So I found a motor at a salvage yard. The guy said it has 7k miles! The 01 van it came out of blew the factory motor so the first owner replaced it. I was told that the local Ford dealership replaced the motor but then the guy flipped the van with the newer motor in it. So my question is how can I tell by the numbers if the guy is telling me the truth and if the motor has the updated heads? I found a date on the motor 1/10/01 Thanks to all!