Tom, The LeMans Spitfires with their fastback bodies (and 1147c.c 4 cylinders) were raced in 1964 and 1965 (and yes, David Hobbs drove) - but that's before the GT6's introduction with its 2000c.c. 6 cylinder. While the 4A and the GT6 couldn't be any more different, I'd be hard pressed to say...