B8A-19578-A Steering Gear Lubricant alternative

[1959retractable]

The 1959 shop manual clearly states, in bold letters, to NOT use a multi-purpose gear lubricant in the steering gearbox. But the part number given in the shop manual, B8A-19578-A, doesn't seem to be listed anywhere for purchase. What type of fluid/grease/lubricant do you guys use? Is there a current Motorcraft version of steering gear lubricant?

[Dave Owens]

I use Mobilgear 600w. Same oil recommended for use in the Model A transmission and differential. If you cannot find that some use straight STP.