Straight after the 1967 race, the CSI (Commission Sportive Internationale - the FIA’s regulatory body) convened to discuss ways to limit the increasingly dangerous speeds in Sports car racing, mindful of what led to the 1955 disaster. It was decided to impose a 3-litre (120-litre fuel tank) on Group 6 Prototypes and a 5-litre limit (160-litre fuel tank) on Group 4 Sports. There remained no engine limit on the Group 3 GTs. It effectively banned the big-block Fords and Chaparral, as well as the big Ferraris and the new Mirage and Lola-Aston Martin and marked the end of an era. The theory was that manufacturers would turn to the use of 3-litre Formula One engines to save development costs.