Inline Power Steering Pressure Regulator

Turn One makes these for Saginaw pumps, they reduce the pressure by use of a smaller orifice. They sell different flow restrictors in different sizes to control how many GPM the pump can produce. You maybe able to solder or weld the hole in your fitting then drill it to a smaller size to restrict the flow in the Federal pump.

https://turnonesteering.com/product/gm-p-pump-or-n-pump-flow-restrictor/