First of all, here is the trick to getting that oil pan off.
Set it back on, maybe just 2 bolts holding into place.
Then remove the motor mounts and lift it about 2" - be careful b/c the back of the engine/front of tranny bellhousing will hit the firewall tunnel.
Now slide 2x4s under the mounts and lower it onto these.
You stil lwill need to unbolt the front diff from the crossmember, and lower it - this should give just enoug hroom to slip that pan out.
Profanity helps coerce it a little too.

Given what you said about the caps - you'll need to do this so you can get a good inspection.

Now for the noise - DEFINITELY the bearing caps being loose is bad news, and is probably teh source of your noise. Those are supposed to be like 70 ft lbs or something.
If they are loose, it means the rod bearings have been wiggling around in there. If so, the bearings are probably toast. And... possibly even the journals on teh crank, too.
Take the caps off and inspect them VERY CLOSELY. You may be lucky; they should be glass-smooth. If not, work is in order.
At the very least, I'd bet you're looking at gettin gnew bearings, probbaly oversized to match teh extra weat from knocking around.

If you can get a complete motor for $350, I'd seriously consider that, esp IF you knwo it's in good shape. Rebuilding thsi one will cost you alot more than that.