My truck pings whenever it reaches aproximately 2000 rpms under load or cruising at 65+ MPH

What is your question?

The truck has 128,000 miles, have checked fuel pressure and is in range, EGR checks out ok. Sparkplugs are motorcraft and have 28,000 Miles and are the right number for the truck. The check engine light is not on. It does not ping if the engine has not reached normal temperature. If I use premium it does not improve at all. any suggestions as to what else I may check to diagnose and fix? Thanks