The input you've given me is greatly appreciated and it is helping me to understand the many issues I will need to tackle as I prep this vehicle. I am familiar with the number sequences you mentioned through postings at various websites. I also became aware that Ford assigned a four-place alpha-numeric identifier to each of their PCM. This is reportedly called a box code and has three letters followed by a number. In addition to being on the PCM, this number sequence is shown under the hood on a sticker as well as in the driver's side door jam area. I have been told that the numbers you have referred to would get me to the right family of PCMs but not necessarily to the PCM that would match a 2001 4.0L SOHC V6 with 5 speed automatic. Ideally, getting one donor vehicle is the best way to go, I would agree, but sometimes the dollars and sense aspect (I got the engine and tranny at an extremely good price) overides. I've always been a little adventuresome anyway. I'll keep you posted on my progress. Any other tidbits to share at this point?