If you have the 460 ZF you'll need a custom adapter plate to fit it to a Cummins, a Ford 6.0 diesel starter, a NV4500 flywheel fitted with a new pilot bearing for the ZF, and a Ford style clutch matched to the flywheel. There are several companies that have the clutch/flywheel set up. Valair is one I sourced from. Southbend is another. There are also several companies that make the adapter. Destroked is the most famous. All totaled, you're probably looking at $1600-2000 in parts. The one I have is to fit to a 7.3 diesel ZF, but the requirements for the big block are the same, just a different adapter.
The Ford ZF 4wd transmissions have 31 spline output shafts. I'm thinking the Dana 20 is a 28 spline which wouldn't fit. Need to check with one of our Bronco guys. The NP205 can be bolted up but not sure about the Dana 20. Member Redhedbronco should be able to tell you.