89 limited slip Ford 8.8 IRS swap help

What is this IRS out of? I can't think of any Ford with IRS in 89... Town Car?
89 thunderchicken... the one I was lucky enough to grab is a 3.73 limited slip out of the turbo car. Im going to attempt to use the part as is and just create mounting brackets... but if that fails I`ll create a new cage. The benefits here far outweigh the hate from other people who see no reason why I should want a little negative camber (the plan with the car is rack/coil over ifs & a t56 its all curves where I live so driving the car stock made life a lot less enjoyable)