sierra column couplings

[misty]

i am extending the column as per the book using the xr4x4 couplings
the book says to cut the column in half, reweld the new tube onto the bottom half. ok so far, the 2 new pieces of tube of which is 25mm sleeved over the old column by 60mm needs a coupling able to take the 25mm in one end of the coupling and 25mm into the other end of the coupling and then the 25mm tube travels on down to the steering rack. does anyone have any idea what this coupling is called or wven where i can get it

hope i have made it clear enough