Do a Ford 203 range box get a 203/205 kit to gm 205.
so ford tranny, ford np203/gm 205.
Most of the 203/205 kit manurfactures will allow you to do that.
Then you could also get the low-max gm 205 with the 3:1 set so you would have 1:1 2:1, 3:1, or 6:1 in the case(s) (damn you lomax not making a ford kit...)
you should be able to get a gm 205 from a yard for a few hundred, finding a ford 203 is a bit harder but still only a few hundred bucks. doubler kits are not cheap.
I tell everyone that the 203/205 is the best thing I have done to my rig. It cost me less than $800.00 to upgrade my t-case to gear driven cast iron case with 2:1 and 4:1... thats about 1/4 the cost of an atlas and should be close in strength (I would say stronger some will say weaker... you still will be hard pressed to break it) only draw back is length and weight (200 lbs) but if you want light you can't really do it cheap...
I do think that selling the gm d-60 and buying a ford d-60 isn't that bad of an idea but if you do that I would still say build up a 203/205 doubler. nice thing about the ford stuff is it already has pretty good size yokes and input shafts. I under stand that the gm d-60 is stronger etc but the ford is high pinion so yeah advantages to both...
Nathan
87 Bronco, EFI 460, d-60, gm 14 bolt, np 203/205, 37 inch mtr's (will be canablized to build an xj at the end of 2010)
http://www.supermotors.net/clubs/superford/registry/194