[loudpedal]

In a road car you wont notice much of an improvement in handling ....assuming both the IRS and live axle are both set up correctly.

The IRS advantage shows up in less unsprung weight, and in the latitude of adjustability.

If I wer u, I would use the T-Bird super coupe irs unit as a base...not expensive and availiable. That is if your chassis conversant and can do fab work. Assembly/fab can be a problem, and can be expensive to send out. The live axle is pretty much of a "hang the springs and bolt it up deal. Hope I helped a little....