right...to do this you'll need the rear beam from a bubble shamped mgR. (the zr160 has 260mm disks weher all others have 238mm disks). You'll be needing the entire hub assy including the calipers carriers disks as well as the hub itself, and of course the handbrake cables. It is a fairly simple job to do but at the same time very taxing if you are doing it on your drive rather than ramps.
The hardest bit by far is changing the handbrake cables, as the bolts holding it to the car will be rusted and easily rounded off so be careful.
Your best bet is to get the entire rear beam which wil include all the bits you need for the conversion (sometimes minus the cables)
There is a brm one on ebay at the moment.
thatx for all the help.im buying the rear beam next friday but i need brake cables and handbrake cables. does anybody know where i can get these from? is 100 quid cheap for the rear axle aswell?thanx for all help