I stumbled across this page ( http://www.modifiedfocus.com/speedometers_001.htm
go to the very bottom) which looks like it can help, except I'm really not sure if I have the PZEV or not. I bought it used and of course they were very hush-hush about where this car came from, and I'm stuck at my desk for another 8 hours so I can't really take a look.
I can deduce that, from the one I purchased which is not compatible, that 1M5F-10849 models are out. Those appear to fit Zetec models (white plug).
That leaves the YS4Z-10849 (not FC) models if I'm not driving around a PZEV, or 3S4T-10849 if I am. Living in the Detroit area... far from Green... I'm betting I do not have the PZEV version. It's certainly not a "performance" quality cluster. Can anybody vouch for the YS4Z models getting along with 2.3 Duratecs?
Where is this information hidden in my car so I can find out, once my shackles are unlocked?