With the crown vic set up your gaining a 1/16" track width due to rotor thickness being more than drum face. You could upgrade to power brakes for relatively cheap. Use a fox body 2.3l booster or even a 5.0 booster they will fit as well and you can still use a dual bowl master cylinder. The only thing that will need to be changed is the Pedal pin because manual brakes use different leverage force from manual brakes. It moves I believe 1" ill have to check mine as I sent mine out to be moved