I know there were a few people on here who were using Dana 70 power loks and ring & pinions in 60 housing with very little modification.. so that would open up the possiblility of a 3.07 gear. Another option that may be doable with some creativity would be a Dana 61 3.07 gear into a 60 housing. I don't have any idea what the issues would be but it might be worth looking into. Even if these gears are no longer available from Dana they should be easier to find than a Dana 60 3.30 gear.