What do I need to know about this?

That part number is for a Chrysler 9.25" axle, not a Dana. The rear cover looks almost like a stop sign. They are strong, but are c-clip axles if you care. The ad says it's 5x4.5" pattern. I'd be interested in seeing what the length is.

It could be worth looking into, but probably not something I'd mess with. I'd find out the gear ratio, verify the bolt pattern, and see how long it is before making any decisions. That axle was used for a long time. It may still be used. I'm not sure.