Here's the video. . .
jimmy - YouTube
Probably unrelated because I think the oil was also leaking "prior to," but I recently changed the oil.
Also, does anyone have any tips for fabricating a new underbody cover?
thanks,
Dan

 

The first thing I would check is valve cover gaskets.

 

After doing some research I'm thinking it's actually the oil cooler lines. Here's a link of a pretty good work-up on how to replace them, and his symptoms and leak location are synonymous with mine.
How To Fix An Oil Leak: Replacing Oil Cooler Lines In A 1999 GMC Jimmy

I also found a good write-up on how to make a modification to relocate the oil lines. Let me know what you think of this. I'm deciding which would be the better repair&replace action.

Remote Oil Lines Modification - Automotive Forums .com Car Chat

 

Actually the oil cooling lines terminate into an adapter that bolts to the side of the engine... It does in my truck at least. Behind said adapter is a gasket or two. Check there for your leak first. They are notorious for leaking.

 

Here's an example. If the gaskets were going bad in the first place you might have worsened the leak when you replaced the oil filter. Check this to see if it helps.

how to change oil filter line on engine side. 97 s10 blazer - JustAnswer

 

Anxious to here where the leak was coming from. Post it

 

the leak was coming from the oil cooler lines. Replaced them and I still haven't finished the job. There's a more current thread on this site about my on-going problems replacing the lines. It can be found in this same engine&transmission section under the title "Car Emergency: oil cooler leak. Video included."
Thanks,
Dan