For blue blocks it would fit 326 to 455 but it just needs to have the correct era heads as Pete says. As he mentioned, 65 and up is the same although I know there is slight difference again around 71 if I am right.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)
