You will have to move the perches on a 1-ton rear, a 3/4 ton rear will bolt in. The Dana 60 is the best way to go, I'm just saying that such an upgrade is overkill unless you're actually breaking stuff already. You can pick up used FF's for $100, a Detroit runs about $425, Disks another $250 or so. If you wait long enough you can find 'em used and built, but it may be awhile. Make sure if you get an axle that doesn't have a Detroit in it that it's open, the Detroit installs inside the open carrier. Make sure you shave the FF before you install it, you can take 1/2-1" off the bottom of the housing to help with clearance. The 8-lug outers are pretty easy to find to, for a couple of hundred bucks, so that you can run 8-lug til you have enough in the Dana 60 fund.