ok, oldholden lists the axels as ...

RRAXLE (Rear Axle / Diff Ratio)
GU4 - 3.08:1.
GU7 - 2.78:1.
GU8 - 3.90:1.
GV2 - 3.36:1 - only applicable to V8 HQ's.
GV4 - 3.36:1.
GV7 - 3.55:1.
G70 - 2.60:1 .