If you go to the top of this page and click on the VIN Data link for '69, you'll have the info you need. However, the consecutive unit numbers on this page don't go that high. That's because the numbers posted were forecasts made by the bean-counters at Ford at the beginning of each model year, so it'll be hard to determine for sure exactly what month your truck was produced, unless you contact Ford and give them all the info on your VIN tag, and they'll forward a 'build sheet' for you for free. The stuff they send is pretty basic though, and has often proven to be less than accurate. A more detailed report can be had through Marti Autoworks, but it's gonna cost.
Here's the Ford link to request your build sheet:
https://www.customersaskford.com/Kate/K ... eSite=Ford