NO. The 9" ford you have is many times stronger and more reliable than an IRS with U joints and half shafts.A jag rear is made for 250 ft/lbs of torque,not the 600 you have.A t-bird is made for 300 ft/lbs. You can get a custom built 9" IRS from a number of suppliers,but then you need a road racing expert to set the camber and caster on the rear end. All factory cars with IRS are set up with oversteer as a comprimise so the driver doesn't put it in the ditch. Set up as a performance alignment will be much more reactive and you will need to pay attention as the car will let go too fast for most drivers.
Perry.
