what will I have to exchange out with the 3 inch lift, or can I just do that when the money rolls in? I have a disco ii 1999

 

Nothing, just look into getting some upgraded driveshafts. I did mine a few years back, it's a great lift kit

 

The driveshafts are a good idea, but they a nicety and not necessary. I'd eventually swap the rotoflex for a u-joint in the rear, but even that I wouldn't do until the rotoflex was getting dilapidated. Hell, I'm on 3.5 WITH a dilapidated rotoflex and it does fine, I just keep an extra in the truck.

You will notice a little change in your steering, it wont return to center as nicely as before, but wont really cause any issues.