I have seen so many 5.3L that have that same position bolt broken off. Idk if it gets hot in that little pocket and it makes the bolt weaker than the others or what.

I tried drilling out the bolt on a set of heads I picked up and the drill bit broke off in the bolt......Talk about a real problem. After dulling 3-4 other bits I found a glass drill bit cut through the broke off drill bit and bolt like butter, and then I re taped it and problem solved.

If you don't want to remove the head than I would live with it or seal it up it leaks

 

i would just let mine go, but i have 2 rear bolts broken on one of my trucks. cold starts in my parking garage are embarrising. it seals up once hot.

 

machine shop repair and save your knuckles...also when putting back together use anti seize(good on the spark plugs too).