Hi,
First post here.
I recently installed electric power steering in a 1966 Mustang. I did not use a kit, I simply pulled a column style EPS from a newer GM vehicle and then spliced the unit into the original steering column.
The results far exceeded my expectations and the cost was less than $200. I designed a controller that automatically adjusts assist level based on vehicle speed, so that the steering feel is "just right" regardless of speed.
I documented (with pictures) how I went about this on a Vintage Mustang forum. If anyone is interested do a google search for "Best $200 mod ever (EPS)" or follow this link to page 7 where the details start:
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Any questions just ask.