put it this way.
with a 4.4FD in 5th you will be about 3000rpm doing 100km/h
with a 4.785FD in 5th you will be about 4000rpm doing 100km/h
redlines in 4.4 tranny are (km/h):
1. 60
2 95
3 140
4 180
5 about 225
redlines in 4.785 tranny are (km/h):
1. 50
2 80
3 130
4 165
5 220 - and it gets there quite easy too !