I am draining, refilling and possibly flushing my 164k miles, 1991 Civic
LX's cooling system tomorrow. I've done it myself at least three times over
the years, but not quite the same way each time. A few questions:

1.
My Chilton's manual says I can "back flush" the system by removing the
thermostat and sticking a "high pressure" hose in the housing, until clear
water runs out the radiator hose (presumably the one disconnected at the
housing). Is this really a "backflush," or is it more correctly a forward
flush but with higher pressure than the engine normally sees? If it's a
forward flush, I'm inclined to skip this, unless someone says they feel it's
worthwhile for a car this age.

2.
If I don't do 1. above, then I'm going to do my best to remove the engine
drain plug. I had it off once before, but as many here know, it's badly
located and tough to remove.

3.
If I do neither of the above, I'm going to fill and drain until the water is
clear. I have the capacity specs. on the engine coolant passages, etc. and
am confident about the dilution I will achieve. I've done this in the past.

No need to caution me about the coolant to use. I know people swear by Honda
coolant, but I've been using the orange Havoline Dex cool and am quite
satisfied (knock on wood).