The same type of diff was in all the early commodores VB-VK except for 308's just that the 253's had a larger front yoke & uni's; and all Toranas (except A9X) had a banjo diff, which has the same crownwheel/pinion as small salisburys. BTW WB 6 cyls have the larger yoke anyway. So the only issue would be if the ute is loaded up and towing, otherwise it would be fine

cheers
Max