Rust Pit Free 340 Federal Power Steering Pulley #2951901 $200.00+

It's possible that I have one, but I did find out last time somebody was looking that there are two different shaft diameters for pulleys that look nearly identical. I'd have to dig through the bins of pumps to be certain.

What year motor are you working on? I do have the pump for my GTS somewhere in the pile of GTS parts to compare to.
He is working on a 72 so a GTS pulley no matter the pump style GTS won''t work. A GTS would have had a cast iron water pump if it was original.