Fabtech 6" lift

[Hammer]

it might be the issue, but can´t say for sure where it leaks. Could it possibly leak somewhere else? I have to clean the diff and see where it really leaks...

My friend told me that he drived one H2 with 6"fabtech lift and he claimed that it handled very differently. Handling was very poor compared to stock h2 .
Is it true it could affect to driveability so much ?

Should I get some leveling kit =(better driveability) ???? otherwise ????
With leveling kit is it possible to lift rear also (without air springs)

My truck drives and handles very good, but I hate rubbing and it rubs HARD.
I love the lifted look and better ground clearance when driving in deep snow, but would not like to lose driveability.