How long are you guys making your pass side high steer arm for a king pin d60? I did some guessing and came up with about a 10" total length. Does that sound about right?

The length depends on how your steering geometry is set up. If you have a 6" pitman arm and a 10" steering arm, you may not get enough steering travel to turn the tires which will limit your turning radius. You need to design the arm around your pitman arm length, location, and travel etc.