Table:
text: 1968 Belgian Grand Prix
Classification
Classification
Driver Constructor_ Laps Time_Retired Grid
Bruce McLaren McLaren - Ford 28 1:40:02.1 6
Pedro Rodríguez BRM 28 + 12.1 8
Jacky Ickx Ferrari 28 + 39.6 3
Jackie Stewart Matra - Ford 27 Out of fuel 2
Jackie Oliver Lotus - Ford 26 Transmission 15
Lucien Bianchi Cooper - BRM 26 + 2 Laps 12
Jo Siffert Lotus - Ford 25 Oil Pressure 9
Jean-Pierre Beltoise Matra 25 + 3 Laps 13
Piers Courage BRM 22 Engine 7
Denny Hulme McLaren - Ford 18 Halfshaft 5
John Surtees Honda 11 Suspension 4
Chris Amon Ferrari 8 Radiator 1

Question: What is the largest grid with a driver from Piers Courage 1968 Belgian Grand Prix?