Hey, better idea!
Since your in the UK, and should have access to an ample supply of old British relics why not use one of those instead?
Its clearly not going to be a road legal car, so why not cut up and old 2500TC triumph? or P6 Rover? or even better an SD1 which already has the room for a large V8, and a live axle which makes installing your 9inch that much easier.
The 2500TC is as light as an R32, but a LOT stiffer, and there are already conversion kits out there for small block Chev V8s, it should be hard to convert the mounts to suit the ford.
Theres also a very large transmission tunnel, and lots of room in the back for cutting and welding to make room for the diff.
Not to mention the gas tank is behind he seat, so no worries about cutting up and relocating the Skyline one.
And quite simply the are so much better looking than the rather bland japanese skyline, the Triumph may be made in the UK, but it was designed by an Itialian.
And of course if its really light weight that you want you can't beat a TR7.