Dart IRS

Many moons ago, people were putting Jaguar rear end assemblies under cars. The IRS on the Jag was mounted on a sub-frame which made the switch pretty easy since it all came out as a single unit. Springs were dual coil-over units connected to the lower control arms.
Memory gets a little fuzzy here. The five lug hub had a 4½ inch bolt pattern and there were some problems hooking up GM drive shafts.