Glow v2

Hello, I was doing a clutch job on my 1997 Boxster and I noticed a very large crack in what seems like the right side rear control arm mount. Would anyone be able to identify this part or provide a part number?

BillC3

Before you do anything else, clean that spot thoroughly, down to bare shiny metal. It's hard to tell in your pic, but that might just be an irregularity in/on the casting or some sort of hardened accumulation. I have seen other Porsche castings that looked like they were cracked when dirty, but turned out to be just fine after cleaning.

That part normally doesn't crack without there also being significant damage to other parts in the surrounding area, like in an accident.

Byprodriver

That's the upright support for the control arm, you should replace it A.S.A.P.