Sean it's safe so long as the adapters are torqued correctly to the hubs and the wheels are torqued correctly to the adapters.
The issue you face is you now have a five bolt pattern on your hubs and your 80 series has a 6 bolt pattern. You would have to use a two piece adapter to make this work, there is a third set of nuts to be torqued correctly, and two piece adapters are expensive.
The replacement hubs are easy to switch out and less expensive. I'd go with new hubs. Add new bearings and seals and your ready to go.