Rock Auto?
https://www.rockauto.com/en/catalog/ford,2008,f-350+super+duty,6.4l+v8+diesel+turbocharged,1440002,ignition,ignition+lock+cylinder,10041
When my truck was broken into in Memphis my local locksmith had to replace the door lock that had a screwdriver pounded into it. They keyed the new door tumbler to match the ignition key. $135 all rolled up.