user: Question: What is the highest grid when the race was retired due to the gearbox after 67 laps?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Mika Häkkinen', 'McLaren - Mercedes', 77.0, '1:45:33.869', 3.0]
SQL:

assistant: SELECT MAX("Grid") FROM "Table" WHERE "Time/Retired" = 'gearbox' AND "Laps" > 67.0;