How can I find out if a part from a different cassis is compatible?

So I found a 1980 300 w116 at my local pick n pull. I have a w126 500 from 1984. And I've priced out a power steering gear box from a remanufacturing site and it's really pricey. Maybe I can get lucky with the scraped vehicle? How can I check compatibility? If not for this exact part maybe something else I need to "restore" my project. Thank you any advice is much appreciated.

So I found a 1980 300 w116 at my local pick n pull. I have a w126 500 from 1984. And I've priced out a power steering gear box from a remanufacturing site and it's really pricey. Maybe I can get lucky with the scraped vehicle? How can I check compatibility? If not for this exact part maybe something else I need to "restore" my project. Thank you any advice is much appreciated.

---------------------------------------------------------------------------
Visit this link to stop these emails: https://zpr.io/t5iAW