Will the rear disc rotor and breaks from an early Range Rover fit on a Perentie?
Fitting disks to the rear of the Perentie will always have some compromises unless you use all the components from the 6x6 or RFSV.
The early Range Rover classic, pre 1984 has a larger diameter in the collar on the outside of the hub, which prevents Land Rover manufactured alloy rims being fitted, but this may not be a problem for vehicles with steel rims. Late Range Rover Classic hubs are the same as Disco 1 hubs and have the same bearing spacing as the 110/non-disk brake Defenders. The RRc stub axles fit internally to the housing and not cup over the axle housing like the 110. The calliper brackets on the RRc and Disco 1 axle housings are welded on parts of the housing, not a separate bracket like the early disk drake Defender and RFSV/6x6 brackets.
While you could use the RRc rear calliper on a Perentie, the brakes on the RRc are underwhelming and many owners fit Defender callipers (front and rear) because the Defender ones have larger piston sizes. It is also why the RFSV/6x6 and KLR conversions use the 4 pot 90 and Disco 1 front callipers on the rear. (You can't easily use RRc front callipers because they have two brake fluid lines to each calliper.)
Disk brake Defenders have different halfshafts, different stub axles, different hubs (Disk brake Defender hubs have narrower bearing spacing) and different drive flanges, so unless you acquire all the components from a Defender with Salisbury diff there will be a different (20mm narrower) track width.
The compromise most people make use is to use Disco 1 or 110 front hubs and accept the 20mm change in the rear track.
The RFSV and 6x6 have a unique hub that retains the original track, original stub axles, original halfshafts and original drive flanges. The callipers are 4 pot Disco 1 or 90 fronts and the calliper brackets are unique, but easy to fabricate as they are flat plate. Now that I have mentioned the above, just watch the price of the disk brake rear axles at AFM skyrocket in price!
