You are right John,
I replaced the 2 in the corner section.
The first was the one next the the A1 bomber crack, and the rock was so hard (30min) to drill the 2.25" bolt.
The second, just below the headwall, was in even harder rock, and I drilled the 3.5" in around an hour.
Hardest stone I have ever drilled in pinnacles, whats more odd is that I did not note this rock quality on the other bolts replaced on the route.
Both anchors were 3/8" x 1" self drive drop anchors. The machine screw is 3/16"