Hi Dave
Just done the exact opposite swapped a 1.4 for a 1.2 on my defender, old box is looking for a new home, there was a very small bit of play in the front output shaft bearing and a tiny bit of vibration around 45 -50 then it goes away once you got past 50 box works ok in hi and low. You could easily change the bearing when the box is out.
PM if your interested
Jock