so I'm looking into doing some modifications to my 04 disco and was wanting a lift and bigger tires but it was recommended to me that I needed to rebuild or "upgrade" my front drive shaft? is it really needed. if so how would I go about doing that

 

There're a couple of threads in here that discuss it under "Drivetrain":

"Write ups" , "How To's" , and "MUST Reads"

 

Regardless if you lift or not you should rebuild your front shaft with serviceable ujoints and centering ball.