The Astro is a mid-sized van made from 1985-2005.¹⁾

See this thread on upgrdading The Big Three.

Past '96 (I think) they're all e-clutch t-cases, but they all swap easily to the venerable NP/NV241 found in anything from Jeeps to Cummins RAMs to Silverados. – tatertom²⁾

If you get one you should drain the transfer case fluid and replace it with Dextron-III as there was a service notice from Chevy about this. It originally came with something else in it which would cause binding at low speeds and cause shuddering when turning. – blahblahsdfsdfsdfsdf³⁾