DONALD - BAD things happen to oils when it gets exposed to temps over 400 degrees, which I think would happen if you heated the oil directly inside the block heater. I put my magnetic heater on the K241 flat-bottom CI oil pan for several years, even tie-strpped it in place so I never had to remove it, just unplug it. By the time it warmed up the oil pan and heated the oil it maybe only heated the oil to 150-200 degrees, normal operating temps.
To use resistors on a tank-type block heater you would reduce the heating capability so much I wonder if it would be worth the effort.
There's companies that make bigger heaters, some even flexible that you could wrap around the underside of a hydro rearend.
Even with my all gear drive snow moving fleet I can tell when I push snow when it's really cold I'm not getting the oil distribution inside the rearend & transmission I really need at least with the Super H. It has 90W in it.... It really doesn't flow when it's cold!
JEREMIAH - Yes, you could loosen the lower adjusting plug, but the whole steering ahaft & worm lowers with it. The little stamped bearing races get beat up anyhow and should be replaced about every time I've taken a steering box apart.
The deal with automotive steering columns is that since about 1970 all cars/trucks have had collapsable steering columns, your not pounding on bearings.