anyone else?  I changed the oil several times, now at 20W50, still doing it.  what would cause it to loose oil pressure?  My first engine did this for a while before it died

Bad oil pump that isn't pumping enough oil.

No, the blow off valve in the oil pump
gets stuck open, this is what killed my
turbo in Moab 2004

Replace the oil pump or fix the blow off
valve, but you have to pull the whole
pump assembly, so you might as well
replace it with a new one

You can test for the stuck valve with a mechanical
guage, it will look like the needle is viberating.

Wild

Note:
DO NOT DRIVE YOUR VEHICLE LIKE THIS. A motor that's starving for oil will burn up QUICK.

anyone else?  I changed the oil several times, now at 20W50, still doing it.  what would cause it to loose oil pressure?  My first engine did this for a while before it died

The other thing it could be is main bearings are getting bad

They will be if he doesn't change the pump!
You can hear bearings that bad, I would get
an oil pressure guage as a perminent addition
to the guages

same thing killed my last engine, but this one only has 60k miles on it, and ran mint when I got her.  How much work is it to do this Wild?  Are parts readily availible?

You will be happier if you pull the engine,
I had to drop the front axle, and driveline,
as well as the center link and the tie rods.

Pull the engine, remove the pan, get the front
pully off and pull the pump, replace the pump,
about $100 new, and glue the pan on after
you clean the block and pan sealing surfaces
off with grey silicone, forget the stupid cork
gasket, it will leak in 6 months.

In short, it's a PITA, but so is getting stuck
someware and rebuilding an engine.

I thought I read somwwhere the oil pump can be removed without taking the engine apart, but you'd know best

Yes, it can, and I've done it both ways,
I would pull the engine next time, reason
being it took me 3 tries to get the pump
sealed right so it didn't leak, it's worth
the extra effort to pull the engine, IMO