You really do want to change things from the knuckles out. Your unit bearing hubs, brakes, weak knuckles and the 4.5 pattern are all things you should upgrade. Simply going from a 30 to a 44 pumpkin is really a minor if not completely useless upgrade. Arguably the worst parts of your 30 are from the inner Cs out. You can eliminate the vacuum disconnect for pretty cheap if that is what you are really after. Look into kits to accomplish it. They are out there. 80s era Waggoneer axles will probably cost much less to swap into your Jeep than a G2 housing but you will need to do some work and buy new rims. The end result will be better in every way though.