LesAlbin: Not sure how difficult it would be to measure. We need somebody with a stock 71-73 car and a 74-on car to be sure its measured the same.
As far as brakes go, I've been looking into that, but got limited response from my "Tims Brakes" issue. What I can tell you is the stock rotors are 9.3". These seem to work fine for 4 cylinder and 6 cylinder cars with good pads. My '72 has a V6 and even with wide tires, the 9.3" brakes work well. I like to limit my Pinto & Mustang II rim choices to 13 or 14", there are some 15" rims that look good on these cars too, but I like them a bit smaller. That said - 13" tires are few and far between unless you get autocross tires. I found P205-60R13 BFG Radial T/As from Coker tire (they drop the car 3/4"). I did this for a M-II that has unique 13" rims. I also am getting a kit from Racer Walsh to put 10" Wilwood rotors on that car (the V8 NEEDS more brakes...). Wilwood has a 74-on spindle 11" brake kit that they say will fit "some 14" rims" 140-14271. I was going to get one and try it on a '80 Pinto I want to run 14" rims on. It hasn't happened yet... I seem to be better at collecting parts than putting them together! Thanks for the 71-73 control arm info!!