[ischmitz]

Doug,

I would consider it highly unlikely that detonation caused a broken head stud. It's the constant heat cylcing that does that. And a broken head stud won't promote pinging either from what I know. The original head studs on a 964 are dilavar. When they corrode they develop stress risers. During my rebuild I upgraded to 993 TT studs that are also dilavar but said to be stronger. Some recommend regular 993 steel studs. There has been a lot of debates about what is better. Some don't like the fact that the 993TT studs are all threaded but I figure that what is good enough for a 993 twin turbo should work fine for a NA 964.

If you want to spend more money there is always ARP or Raceware as an alternative. For what is worth,
Ingo