You don't have a torque tube in your 1 ton now do you?
A 72 1 ton rear is most certianly an open driveline, no torque tube. So you could swap center sections but you'd have the same setup is my guess. Other than a possible gear ratio change.
If you want a faster gear ratio than what you have now then first figure out what that is and what the ratio is in the axle you're looking at. While the new one probably is faster geared don't just guess and count on it, lots could have been changed on either truck in the past 40 or 60 years.
