This is essentially the original write-up that I saw regarding the IRS install: http://www.mouthbreather.net/IRSSWAP.HTML .
The write-up is very good and well detailed, however, I had one issue with some aspects of the install that I think may have been overlooked. My main concern was that the author made no mention of reinforcing the frame rails that the upper subframe bolts to. The frame rail is shaped like a "U" so the top portion is nothing but some 16ga sheet metal. Installing some oversized washers is not sufficient to prevent collapsing the frame rail, in my opinion. I decided to use some 3/16 steel plate and tube to reinforce the frame rails so there is no chance of any collapse.
Here's the 1/2" grade 8 bolts as well as the plates and tubes that I cut to size:
I oversized the holes in the floor to give me a little margin of error with lining up the reinforcements:
The spare tire well is so close to the driver side frame rail that I had to cut a hole in it to drill through the inner side of the frame rail:
I'll weld it back up and install a grommet in the tire well in case I ever need to access the subframe bolt
The passenger side needed a little bit of trimming so the subframe mounts would sit flush:
Here are the welded reinforcements. The notch in the one smaller plate is so it clears the welded nut inside the frame rail for the old quad shock mount.
Mocked up in the car:
Removing the old axle snubber so the upper control arm will clear:
Mocked up the passenger side control arms and hub:
And the moment of truth...tire clearance:
The wheels do stick out a bit, but the camber is not set yet and the car is not sitting under load, so I'm confident the tire/fender clearance will be okay when everything is bolted together and setup properly.