Beyond the math word problem (answer, $102) I'd say to check the taper and depth there of. The proper fitment to the spindle would be critical.  Also, do the mounting holes (or modifying the holes) offset the ball joint as it mounts on the arm? That could throw the camber out to a point it can't adjust back to spec. but otherwise I agree that if the part is adaptable use it.  all the 71-73 suspension stuff is expensive due to its age and smaller sample application.  In my mind people should be snagging every decent rotor they can find because I believe they are over $100 too..

My bad. Thought the 27 was 25 must have caught that from the "5" in the 1975. Why was it that I always saw the error AFTER the paper was corrected??? So how did they fit? Or better said what did you do to make them fit?