More gears to stay in the torque bands.. But thats an open ended question because...
1. They will defiantly not be the same rear IMO.. 2. The six speed if you can get the 3;92 rear would be way better. 3 The 8 speed most likely has 3;21's..
So it depends...
6 speed 3;92 tows 10000.... 8 speed 3;21 80000.... From my findings...