It's a common problem on the older trucks that had the bypass (yes, you were correct) valve staked in place. The oil will bypass the filter and you will risk damaging the motor. If you can find the pieces (there will be the spring, the disk, and the washer ... goes back in in that order), you can stake them back in place. If you are missing any of those you need the updated header with the snap-ring retained bypass valve and pressure regulating valve (on the block side of the header). If you need to get the header, buy it from someplace like Tousley Ford Parts (now known as AutoNation Ford White Bear Lake Parts).
Oil Filter Header (updated snap ring retained bypass and regulator valves)
(Ford) F81Z-6881-BA List: $245.87, Online: $121.70 (just a tad cheaper)