I realize this thread is old but how can I get that information for a 1MZ-FE engine? Seems you need a VIN number but if I had that I would know the year the engine was made. Even Lexus couldn't help me out. Where did "Go West" get that data? In my case I have a '99 RX-300 but the engine was replaced before I bought the car. I have the engine serial number but that is it ... Any help would be appreciated .. Thanks.