You're going to have to build new shock mounts anyway because with the axle 40mm forward and the added travel, stock mounts don't work.
You're going to have to build new bumpstop mounts anyway because they won't work with the new axle position either.
The added work is in moving the spring plates on the axle inboard, and cutting the spring hanger off the chassis and sliding it inboard. You'll also need a longer U bolt for the driver's side because the WT one will be too short.
Basically it's chop everything off the chassis and move it inboard. It adds about 4 hours to the job.
The end result looks a lot neater too.
This is a WT RUF - the old crossmember was cut out, the new one welded in on the chassis extension, and the spring hangers replaced to WT width. It's OK, and has been on this car for years, but it's messy looking and resulted in this car needing more rim offset to allow steering lock.
(Incomplete in this photo)
Here's a WT that's had the front springs narrow tracked, and vitara power steer added.
And here's another WT car with narrow tracked front spring spacing.
This car was actually built with WT spacing but we found the steering was too compromised so we swapped it to NT spacing in an afternoon. This car as a new large diameter crossmember under the radiator and we brought the steering box a long way forward, over where the stock tube crossmember would normally be. This was done for speed really, but allows a vitara drop pitman arm to work quite well in this very low application.
Steve.