I know that the calipers are unique to this model, but what about the pad retaining pins? So the calipers on the 4,2 Mk10 are different?
There are no new Master Cylinders for the G either. And there have been problems with the repair kits, in that the seals and O-rings have not had the right dimension.
I don´t want to change to XJ S1 15” wheels.
as far as I know, from my 420G, all brake parts are readily available, except calipers, which are rare & expensive
There are 3 brake systems on MK10/420G
3.8 dual booster, all parts different to later models
4.2, Dunlop 90 booster split with band, single master cyl, all new brake parts
420G Girling Supervac 100 booster, new master cyl (both same as S1-2 XJ)
different calipers, pads, discs
The 2 main suppliers in UK have all these parts listed for 420G, except I do not know about the booster, I had it rebuilt by a specialist,
The master cyl sleeved in SS
The 4.2 MK10 parts are mostly very hard to obtain, many have been retrofitted with 420G parts