Finished swapping the engine out of my 90 GL with the screaming manual
transmission (bad bearing), and into my 90 non-GL automatic (whose engine
was making a Bad Noise). When I finally added all the requisite fluids and
hooked up all the wires, it started right up. Ran it for a while, and then
noticed a small puddle forming under the back. Coolant, or course. The
water pump to engine case O-ring is no longer sealing. Never leaked before,
when it was in the GL, but we all know that's what happens, right? I
changed all the hoses, replaced the plastic 90 degree bend hose fitting on
the right side by the pulley with a metal one, changed the fuel lines and
injectors,and changed the ossified and leaking flywheel/flex plate crank
seal and O-ring.

So the lesson I've learned is, if you don't know when the water pump seals
were replaced last, you might as well replace them if you have the engine
out, even if they don't leak. I've just gone ahead and ordered a whole new
water pump, because if I'm going to rassle with getting the old one off
with the engine in, I want this to be the ONLY time I do it.