I looked into this before deciding on the CPP power steering kit , which I believe uses a toyota box like yours. Besides a radical change in the geometry of the column, I wasn't able to find anyone who makes a hi-steer arm for the closed knuckle Spicer 44(assuming you still have the factory front axle). If i could find a later model HP Dana 44 with disc brakes, I would definately do it, but not worth the hassle, at least to me, for the original axle.

 

1973 was the first year P/S was available for F100/250 4WD, but it was power assist P/S using the manual steering gear box for 1973/75 F100 4WD & 1973/77 F250 4WD (High Boys).

Ford/Saginaw P/S wasn't available for F100/150 4WD until 1976; 1977 F250 4WD from serial number Y20,001 (not a High Boy).