Kinda... it's not super simple but it's not that hard either. If you go back to the beginning of this thread you'll see more detail on how I did it.
That said, you'll need a new cat back exhaust (Cobra specific, and I had to modify mine on one side to shorten it), new brake lines (part numbers at the beginning of this thread), you'll have to remove the factory bump stop braces on the chassis, and you'll have to drill a couple of holes in your frame rail for the mount points on the rear. Also the pinion flange on the IRS won't work with your stock driveshaft so you'll have to swap one or the other to mate them up (I did the pinion flange and SCREWED up my gears not knowing what I was doing, if you don't know how to do the gears have this done), and the fuel filter is HARD to replace with the IRS in so do it while it's out. The whole unit is much wider and you'll have a hard time finding wheels/tires that fit without rubbing, and pretty much the max you can fit is a 9" wide rim with a 6.75" backspace with a 275 tire. Also I think the front bolts for where the cradle mounts to the lower control arm spots you'll need to use the larger bolts and might have to drill it (the TQ box bolt holes) out to fit them. Obviously all the IRS's are 5 lug so you'll need the fronts to match it and the easiest way is to use the Cobra front brakes and appropriate master cylinder/booster. You will also want your front end struts and springs to be aligned with what you use in the rear, spring rates are much different for the IRS and your SRA springs will not work. I don't recall if there's much else I'm forgetting, but it's also WAY easier to install new bushings in the IRS while it's out and I highly recommend you do that first, at least get rid of the rubber bushings so you minimize wheel hop.
