1041989
The D35 is the weak link. The transmission and t-case are very strong and have been used in a few v8 applications from the factory. I wouldn't worry about the front axle unless you're going over 35"s with the tires.
As for replacing the D35, it depends on what your future plans are, with what's listed in your sig you should be fine, however if you're not careful with the gas you might break stuff.[addsig]