You would be much farther ahead to simply rebuild your T-bird suspension in a performance direction. Take the car into an alignment shop and get a good diagnostic. There are a number of rebuild kits out there to improve the suspension and steering that are guaranteed to work. Trying to improve a large intermediate like the T-bird with small car parts (MII) is not going to gain you anything but headaches.
A set of poly bushings, good shocks and some low profile tires/wheels will put you well on your way without tearing the car up.
Mark