Exact details regarding outer
CV JOINTS ST170 
There are two possibilities for this, however I am not sure if these are detailed by a model year.
Codes as per supplied by DAVE MAC PROPSHAFTS (prices as per 2008)
OJ-1389, 25 spline at wheel, 24 splines on bar @ £33.00 each +vat – which I have on mine.
OJ-1495, 27 splines at wheel, 26 splines on bar @ £26.94 each + vat