Humvee 6.5L engine block coolant plug

[Mogman]

Would you have any pictures that you could post to show some of what you're referring to? I have a drip that I thought was antifreeze but looks like may fuel also. I can't smell and tell for certain but makes me wonder if this could be my issue. I have a '08 6'5l turbo and has a tag of a rebuild on the rocker arm cover.

That was referring to the drain from the lifter valley, If you engine had that plugged and you had a leak near the injection pump that valley would be full of diesel. It would not "cause" a leak unless your truck sat for a long time with the lifter valley full of water.

Where is your drip?
Edit, if it is on the sides of the engine a bad return line would be the most likely cause, you do need to figure out if it is coolant or diesel.