Did valve covers and and found T stamped into them. Was curious what the code stood for. Truck was engine swapped before I bought it and non turbo now. What does the T mean?

 

Also, why the heck would Ford put a stud through a valve cover? It's not a head stud right?

 

Too small to be a head stud. All my valve cover bolts go through my valve cover. I think there is one or two or three valve cover studs [to support a strap or another item].
Also, it might help to include your vehicle's specs.