It's a 9/16" head on the bolt, not sure the diameter. A typical heavy lug I'd say. Unfortunately it cracked off down in the hub, rather than just the head of the bolt, or I could take the rotor back off and get a bite on the bolt.
I'm thinking 165lb/ft is too much, and can't remember where I read that, and can't seem to find the actual specification.
Oh, and you'll be happy to hear I snapped the brake line off as well... so now I'll need to replace the metal line from this side to the next. I guess it's not that bad considering I have the 3rd rear rubber hose, which attaches to the one I broke.
This is by far the worst brake job I've ever dealt with. Keep the nuns away.