G day Toothman
About 12 years ago I did a right hand conversion on a 76 F250 crew cab and used a 260 or 280 C Nissan sedan power steering box. I used a XE steering column and there was at the time a auto electrical shop in the west end in Brisbane (I cant remember the name)that used to sell pitman arms to suit F series with the nissan spline. It worked fine the only improvement would be the pitman arm could have been a bit longer as it didn't allow the steering to quite reach the steering stops. I made steering hoses to let me use the pump that was on the 460. I fabricated all the mounts etc and at the time I think parts only cost me about $ 450 in total (oh for the good old days)