read the posts in the J forum. I dont think the plumbing was the biggest issue, it was mainly fitting the downpipe past the steering column and the oil filter.. http://forums.nicoclub.com/zer...40186
I figured the VG even N/A would be way heavier than the VH45.. I'll have to do some more research, but the VH is around 500lbs with all its accesories, and the VG30 is about 600lbs with the same accessories... Twin turbo might be a little heavier considering its got beefier manifolds, and of course, 2 turbos.. 
I still think that since the J30 came with a VH in japan (VH41, but still, basically the same engine in Japan) that a VH swap would be way easier.. Look at the thread in the VH forum, one of the posters thinks you can even slightly modify the stock mounts and bolt it in, which would be awesome!
