Yes they can, but you will be building a diff, with all the work that entails. It is fairly easy to source other ratios from Jags. XJS V12 pre 92 has 2.88 powerlock. V12 and 6 bangers have 3.54s, V12 and some sixes with powerlock.Series 1 and 2 XJ6s have either a 3.07 or a 3.31. XJ12s have the same offerings but with powerlock. Anything older than thatwill be an earlier diff style. The brakes will not adapt easily. (the early cars had dunlop calipers)