I just looked at the tech section but what I need to know is which way to adjust the link rod to get the selector further towards top gear? Longer or shorter? I was going to try a small blind adjustment as the box feels like it's not going fully "through" into top gear.
The detent plunger on the selector cam controls the positioning of the selector forks for any one given gear, you simply have to adjust the rod, so that it is correct for the detent plunger on the cam, ie so that you don't have to push or pull the arm on the end of the cam to get the clevis pin in there. Ensure that the selector mechanism is sat in the small detent for the little plunger and spring behind it, as sometimes these are left out.