For 67-up cars, it is most useful to post the actual build date.
+1 Build date (Projected) is no more useful IMHO in comparing details and trends than comparing Ford VIN's. We know that when using those you can be off by a month or more. Current greatest period between real and projected I have is 8 months. In your case its a month off and yes I went back and correct my last response in the rear spring thread
Another example of the importance of the real date for 67 and up cars is the running changes research current being conducted and ongoing is that the only thing (data) we can trust is that real date and car details from those cars with real dates are the guide posts for all findings.
That is the nice things about doing San Jose cars in 67 is that we have access to all those dates without asking for Marti reports from each. This from a guy that has spent three days so far entering each and every 67 Shelby's real build date into a usable spreadsheet so that we can narrow down those running changes that Mustangs and Shelby's share.
If only we had the same from 65-66
Bill now will just have to look up your real build date everytime you post a finding. I suggest others now have to do the same thing if they want to compare what they are looking at on their car. This is also why we often ask if, when members post a "build" date - which one it is.