clutch fork

Call Brewers, their knowledge is impeccable.

Have your trans case # handy, and know what kind of car it came out of, also what bellhousing# you are using.

This may give them something to go on and maybe they have the fork just for you as their website does not have technical solutions for different applications but they have always been able to steer me in the clear with the right parts/info.

Some forks are aluminum, some are mild steel.
If a magnet sticks to it, it's mild steel and very weldable.
I've never seen them in cast iron, but I would call Wayne.