Sorry I didn't get back to you sooner. It didn't hit me until I looked in the service book, it's the same engine used in the S10. I've done many S10s, but Cavs are scarce around here.
Good to hear you got it off. Can you see any signs of discoloration around the little breather hole (holes?)? If the weather turned cooler where you live in the last few weeks, it's a good chance it was coming from the pump. For some reason the first cold snap makes for leaky water pumps and heater cores.
Whatever is in the way will have to be moved. It seems like if it came out, it should go back in. I recall on one car I had to pry against the engine and the body to flex the motor mounts over, to get a water pump back in. I can't remember what car that was on though. Just make sure you clean all the sealing surfaces the best that you can. The cleaner ,the better.
New pumps have a stiff feel to them because of the new seals/bearings. Do you plan on flushing out the old antifreeze? Sometimes it's easier to remove the bottom hose from the radiator than to fiddle w/the drain valve.
Remember one thing: When you get everything back together/before you install the fan belt, fill the system w/coolant and spin the water pump pulley. If you bought a "cheap" rebuilt pump, it'll help prelube the main seal, and less chance of it leaking prematurely.
Glad to hear you're doing ok.