Glenn, I am under the impression that the stock flow on a Mustang rack is 2.0 GPM. I just picked up a KRC pump with attached reservoir and did the AN conversion on the rack. If you are running a fox rack, then there is no reason for you not to be running a newer rack. The inner tie rods are interchangeable and the steering feel is supposed to be much better. Here is the link to the adapter fittings. You can buy off the shelf stuff and cross thread it into the hole, but I could not find anywhere else that had the correct metric fittings to convert to AN.
https://www.maximummotorsports.com/M...004-P1001.aspx

https://www.maximummotorsports.com/S...-Fox-swap.aspx