The GA or GAA was commissioned by Ford in May 1972, when Ford realised that the Cologne V6 based Weslake OHV V6 engines used in their Capris which competed in the European Touring Car Championship had been modified to the point that no more performance could be extracted from them. Mike Hall, who had already designed the highly successful Cosworth DFV and BDA engines, took on the task of developing a whole new engine based on the 3-Litre Essex V6 block.