You'd have to do a bit of a search on that Gus to get across all the details; but basically early in the 3dr's life they used H13 bar, and towards the end of the production Ford replaced it with a new bar called H14 which was a fraction longer in the arm which had the effect of increasing castor and settled high speed handling a fraction.
It's since become a popular mod for those running earlier 3drs. I may be wrong but it may have then been carried over to the Sapphire subsequently but can't recall if it was done for 2WD and 4WD in equal measure.
HTH
Cheers
Iain