wrote:

On Wednesday, November 13, 2019 at 2:23:11 AM UTC-8, Gunner Asch wrote:
I picked this up the other day and am brain locked in what its called.
Its used to machine engine heads and other similar work pieces. One
clamps a head to the top of the fixture, and swivels and rocks the
fixture to adjust it for boring, milling etc etc.

It is typically mounted on the table of a vertical milling maching.

https://photos.app.goo.gl/oTCDT2wiHH35sXM5A

A trunnion? But, it looks WAY too light for milling. Maybe could be
used on a router or for VERY light milling cuts.

Jon