Every time I do a filter & oil change on my series II ...it even sounds better!
I would not wait until the oil pressure begins to drop, just change it at regular intervals.
My oil life monitor (based on city/hwy driving) generally hits 20 % by the 4000k mile mark.
Oil/filters are cheap. Engine rebuilds are not.

I use Mobil 1 and I still change the oil every 3k.

I do the same here. I use Mobil Super 5000 conventional though

I use Castrol part synthetic and change it every 5 to 6k miles. In my opinion anyone who goes over 10K miles on a oil change is asking for trouble. I don't care if Mobil1 is suppose to be the best oil on the planet, there is no way Id go over 10k miles on a oil change. As mentioned oil and filter is cheap compare to a major engine repair.

Agree...

3 months/3K with reg oil...

5 months/5k with synthetic....

Once I went 6K miles, on an oil change.....

Service Writer told me, you should never go 6K miles on an oil change....I said the monitor said I STILL had 40% left....he said you can't trust those....I said, then why are they in the car? He said, change your oil every 3K....I said why, I use Dexos oil....he said what'* that? I said GM'* been using it since 2011 vehicles were made......Service Writers.....they try to sell you all this maintenance, yet haven't a clue what they are talking about.....can't really blame them though, probably never lifted a wrench in his life.....

Gm has come out with several updates on their oil life monitors within the last couple of yrs. There have been numerous concerns of customers goin over the 6k mile mark and still showing over 50percent life left and there is little to no oil left in the pan.

I wonder if there is a calibration problem with different cars/programming?
I check my engine oil Weekly, and all the other fluids. I have noticed that I need to add a half a quart or so, over the 4k mileage change I do.
I still like to keep my oil on the full line.
I have been using only synthetic engine oils, and Change oil at 4k miles, regardless of oil monitor.

You can even step it up to a bigger filter also. Just ask for a filter for a 1996 or newer 4.3 Vortec. STP S3980. Its the same diameter, but its longer which gives more filter area per square inch which also takes about 1/2 more quart to fill.

all of my cars new or 300k use a quart by the 5000 interval i do

Good recommendation Mike. I use the tall Napa Gold filter #1036 which is a Wix as far as I know, for the 3.8 I wonder if that is the same height as the STP S3980..?
My question is would a taller filter change the oil pressure reading in any way?