It's not THAT easy to get a live front axle on a tammy.  You have to fit in a transfer case and figure a way to get the driveshaft under the gearbox back to the front axle.  Other option would be to ditch the tammy gearbox all together and go aftermarket that has 2 output shafts.  Like this.
http://www.wtbcar.com/shopping/index...product_id=154