one last question. how long does it take to install the new brake lines? i have 3 hours with the lift at my friend's shop.

Shouldn't take that long. Just make sure you take your time not to strip/break anything, and take your time bleeding the system. Make sure the master cylinder doesn't get empty, and make sure not to press the pedal fast, or you'll just end up with tiny bubbles of air instead of actually bleeding the system. Pump the pedal slow, take your time.