AS indicated there were two arbs for the 3 door the H13 and the H14, the H14 was also the one used on the 2wd sapphy, a lot were changed under warranty after comments in road tests and customer complaints.
It does as said alter the castor which could also be done simply by using a spacer under the dished washer on the arb to sit it further forward, a lot inc myself prefer the early arb for it's better turn in.
tabetha