I'd just retube your old one for now, you can get the tube for half the price of that spacer. It's really not that hard to get it fairly well balanced either, just insert the ends into the new tube, jack up the front end, bolt your ends up, and spin the front tires with the transfercase in 2wd. Just watch the wobble, and give it a little bump till it looks good, and give it a few tacks.