I have this very same thing now, good to use the search on here! My intake bolts were loose too, used the SM for torque info. 8 of the 10 required at least 2,3 or 4 turns to proper torque, and just like orandaberg, my driver side rear(closest to the firewall snapped at torque. WTF now I thought surely I will have a bad leak now? Cleared the codes and started it up drove around all day and no CEL on or code,
So rather then preform a complete intake manifold removal and hopefully the stud is sticking out (which is not that hard looking at the SM) I will just leave it be. I use to have plans for a nice wax job and such, now I do not even bother washing the dam thing.