Difference between Dana M65 and Dana M70

[gpintler]

I have a gen2 with a Dana-M60 [3.55 gears] rear end in it --- can I replace it with a Dana-M70 [3.55 gears] ? I don't know the difference between the M60 and the M70.

 

[Cummins12V98]

Usually it's a 70 in the Auto trans trucks and 80 in the Stick trucks.