Very wary of the gearbox seals. Told 2/3mm in but the ones on my original box(never touched) are nearer 4mm in? Not so much worried about the distance box have put two in and not happy they are square. Going to make some kind of?? gubbins to put another set in square.Reason I'm so paranoid is I've put one in off the square in the past. P.I.T.A. when you thinks the cars finished and it starts dripping gear box oil.