* Your truck itself: The easiest way is to count the lug nuts on one wheel and measure the distance between two lug nuts that are opposite each other (this gives you the diameter of the bolt circle). This is the most reliable method.
* The owner's manual: If you have the original owner's manual, it should specify the bolt pattern.
* The vehicle identification number (VIN): A VIN decoder, either online or through a parts store, might provide this information. However, it's not guaranteed.
* A parts store: Providing your VIN to a parts store specializing in classic Ford vehicles is your best bet if you can't find it elsewhere. They can look up the correct bolt pattern for your specific truck.
Common bolt patterns for that era include 5 on 5.5" (5 lug nuts on a 5.5-inch diameter circle) and 6 on 5.5". But don't rely on this; verify it for your specific truck. Using the wrong bolt pattern is extremely dangerous.
