The box swap was fairly simple. The road feel is much better than the stock box, but I wish it were more of a variable assist. It's still a bit easy to steer. You will need a new rag joint & some adapters for the hose fittings to convert to metric.
If I had it to do all over again I would let Lee rebuild the stock box to the way I want it to feel. Lee's rebuild just costs more than the Iroc swap.