[1948F-1Pickup]

It's a pretty common mod in the vintage Mustang world and
becoming more popular daily....
Here's some of the details off the thread-

The cars with "fail safe" electric power steering....
2004-2009 Toyota Prius
2009-2013 Toyota Corolla
2006-2011 Toyota Yaris - (With ABS works in Fail-Safe).
2006-2011 Toyota Yaris - (Non-ABS needs VSS signal or flashing LED)
2007-2009 Nissan Versa
2009-2012 Nissan Cube
2012-2014 Kia Soul

The hot ticket for the 65/66 Mustang, which has a similar 1-piece
shaft from the steering wheel down to the steering box, like what
I'm guessing you'd also have on a '38, is the Prius or Corolla setup.

There is a packaging deal and I don't know what your '38 underdash
space situation is..... I'll post a photo of what these items look like.
It's basically a cut, and section deal with your factory steering shaft,
plus some wiring.
By "fail safe" I gather you've still got steering if the electrical power
goes off..... you just don't have power assist.