Since you've got a BBP, 1/2 stud set up I bet the #4311 Mr. Gasket studs would work for you. I know its a 7 1/4, but since it uses the larger diameter studs I'd bet they used the same ones as the 8 3/4.
Both the Mopar and Dr. Diff kits only move the springs in 1/2". Mopar claims 3.4", but I measured them, they're only a 1/2" different from stock. That route also requires welding on new perches, and since the 7.25" in question is "temporary" it would be much easier just to replace the studs.