If any members have ideas as to how to make this work on a 1641, please chime in. I'm not sure if the hydro pump on a 1641 has an aux out to use for the steering.
My plan was just to use the send line (from the lift valve) going to the power steering unit inlet first with a return line to the hydro. The aux from the power steering unit would then go to the lift valve with the return from the lift valve tee-ing into the return line from the steering unit that is already connected to the pump. The R and L hoses going to the steering cylinder. Hopefully there will be enough pressure to make this work. Steering might be a little weak if using the lift valve at the same time.
With any luck I will be able to couple some of the existing steel hydraulic lines which have some tight bends to make this work.
If my ideas don't sound quite right, please let me know what you think needs to be changed. Help from the members is always appreciated!