I'm glad I noticed it, when I go out and do measures for the store a lot of them are about 30 miles away either north or south. Much better to be 2 mi away from home when you discover the issue. Fortunately it didn't leave me stranded but I was able to drive to the job I was heading to an accomplish what I wanted to yesterday. It's about a 20 mile round trip.
Though my S10 with a 4.3 is a v6, it shares the same water pump at this bigger brother the Chevy 350. It's not as easy getting the bolts out on this little V6 because of clearance issues.
I guess if I got it out it's somehow going to go back on.
Well, it went back on, no leaks.
It was a bit of a pain but I did something that made it easier.
There's two gaskets on the pump, one on each side and getting it up into place and having the gasket stay in place can be one of the difficult parts.
I put a small smear of permatex gasket sealer on one side of the pump and let it tack up while I had lunch. With a gasket now stuck to the pump side I put a thin film of wheel bearing grease on the other side and slipped it up into place then put in the bolts.
In theory, water pump gaskets and thermostat housings don't require any sealer. Instructions if you're lucky to get any, don't mention sealer on the gaskets.
There's a reason for that.
Sometimes you need sealer simply to hold the gasket in place while you install the part.
Well I had the pump off I noticed that the plastic idler pulley on the serpentine belt was kind of wonky so I replaced that with a new steel one.
Here's a couple pictures of the old one, looks like it was slowly collapsing. I think it's original to the truck, 288,000 miles? Not bad.

The new one's going to outlast the motor.