I believe there were at least 3 lower ball joints used on the MkIV.
Early ones were MK III type and would have been used up to perhaps 1986?. At this point new sealed ball joints with a two cross bolt fixing were introduced, accompanied by new two part wishbones made of rectangular box section to suit. At a time I do not remember, a further new ball joint was introduced with slightly different mounting hole spacings, perhaps by 5mm? I think all these later ball joints came in QH boxes.
Peter
Early ones were MK III type and would have been used up to perhaps 1986?. At this point new sealed ball joints with a two cross bolt fixing were introduced, accompanied by new two part wishbones made of rectangular box section to suit. At a time I do not remember, a further new ball joint was introduced with slightly different mounting hole spacings, perhaps by 5mm? I think all these later ball joints came in QH boxes.
Peter