I would make them power. Did it on a 69 mustang convertible from 69 Couger parts and worked well with only drilling two small holes and wasn't that hard with my lack of experience. Ford even made a couple of 69 Shelby's with power windows. A 71-73 should even be easier, but I think I heard it might be different glass from crank windows for the motor to fit on a 71-73, but not sure. I don't think I would buy a 71-73 with out factory power windows again. The sportsroof looks so much better with the rear windows down