There was a factory set up offered for TF trucks, quite rare and pricy if you find one. Any other PS conversion will require modifying the existing column or replacing it. I used a Toyota conversion. Installed it when I did the V-8 conversion in 2000.
It works well. I would estimate that a PS conversion kit is currently about $750, Disc brake kit with booster, etc, about $700. A complete Mustang 11 front end is probably close to $2500.
labor not included.
Fred