Greg Bender
http://www.thisoldtractor.com/gtbender
I extracted much of this information from Paul Linn in personal communications.
The operating pressure of the hydraulic oil for the torque converter is 25-29 PSI. Because it is this low, standard oil lines can easily replace the stock lines. There is no need to source new fittings. Just cut the existing pressed-on hose clamps off, replace the hose, and clamp in place. As is mentioned in Guzziology, the line running from the reservoir tank to the inlet (left) side of the hydrualic pump is under suction. Be sure to use a thick-walled hose in this application to prevent it from collapsing.