Thanks for your help. The 1973-1987 GM full size pickups steer box will not work for me becasue plan on keeping rear steer due to the geometry of the frame.
I'm converting my 37 Roadmaster ifs to ball joints and disk brakes similar to the wiki:
The difference is that I'm using the spindles and brakes from a donor car which is a '95 Roadmaster. The spindles will be swapped left to right to maintain the '37 rear steer. The ackerman angle aligns well with this swap.
This change means I need to handle power steering differently than the second part of the instructions found at:
The steer arms on the 95 Roadmaster spindles are too long to allow rack & pinion unless I go with a very expensive after market r&p.
I plan on use a center link with a steer box mounted on the outside of the frame because the frame is very narrow at the front axle.
The idler arm length willl match to the pitman arm length.