 de Klerk and Pretorius won three of the South African non-Championship races in 1970 and 1971.In 1970 Derek Bell competed in the Tasman Series using a BT26A fitted with a Cosworth DFW, a 2.5 litre version of the DFV.Bell's best result was 2nd in the New Zealand Grand Prix, but engine troubles forced the cancellation of the Australian leg of the series.