Had the head checked and it's gtg valves etc.. Head gasket looks okay... The plenum gasket and lower man gasket/marks look a little funky tho... I'm thinking vacuum leak around that runner

There's more **** to unplug and re plug than bolts

 

If #8 is clean, completely clean with no fuel at all, then I'd suspect the injector isn't firing. Either the plugs bad, the plug is not getting power, or the injector itself is bad.

Also you should figure out why it overheated. More than likely you need a new fan clutch and the radiator should be cleaned (at a radiator shop) or replaced. You can't work these trucks "too hard", the cooling system was designed to cope in the most extreme conditions at full load.