Yep, I did find this
ford vin decoderBut it doesn't seem to reference the axle ratio.
I finally found this site and will check when I get home from work:
axle ratioSo if I find out this is correct, I hope this helps someone else.
"The plate layouts vary depending on the model year, but in every case the axle code section is clearly marked as either "axle" or "ax". Ford axles codes contain one or two character. Any code beginning with a letter (an alpha code) indicates the vehicle is
equipped with a limited slip differential, except as shown below."
edit: corrected URL's, see what happens when I post from work when I'm busy