The guy i puchased this one from said it works for 67-72. Although i installed the other one i had on mine which is the same size and it worked fine, i just had to adjust my tie rods
The one on the bottom is a 67-72 V-8 AND /6 centerlink. They are the same both motors.
It might be able to be installed and "work" on a 64-66, but it's not right. The pitman and idler will be angled and the bump steer will be changed because the inner tie rod is moved outward.