Pete,
There are a number of aftermarket sources that sell what is now referred to as a "Series 400" power steering unit. It is really a recreated Toyota box (84-87 4x4 truck) which now incorporates a cast mount that lines up directly with the existing mount holes on a TF frame.
I converted my 56 in 2000 and it works great. I used the stock column which I modified to adapt to the PS box. I also retained the entire column shift components for the 3 speed overdrive. I have done several of these conversions. If you wish to contact me, I can provide additional information.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine