The Rover P4 110 came from the factory with a 2.6 L Rover IOE inline-six that made 123 horsepower. However the 1964 model owned by Ian Portsmore no longer has the inline-six but is instead powered by 552 ci big-block Ford V8 connected to a C6 three-speed automatic transmission. The combination resulted in a personal best quarter-mile of 11.3 seconds.
Source: Mk1Kieran