180 is a bit on the high side, as the 160 was probably more common back then. If it's not boiling over, the radiator is doing its job, but if the gauge reading has you worried, dropping back to a 160 won't hurt anything. If you plan on any winter driving, the heater won't work well with a 160 stat, though.
The brake drum is probably rusted to the hub, and should respond to a little penetrating oil and some moderate hammering between the lug studs to break the rust bond loose. Did the other drum slide off the studs, or did you have to remove the axles, and take the hub nuts off?
Jerry
