Low oil pressure, only slight fluctuation with throttle
 

Truck in question is a 2008 originally 5.3. It had some problems so I got a 6.0 l96 from a donor vehicle. The oil pressure was 40 at warm idle wile it was still in the donor, don't know how it reacted with throttle also don't know what weight oil it had. I got it swapped over and filled with castrol 5w30 now it only has ~25# at idle and only goes up to 30 with throttle causing the gauge display to show a oil light and low oil pressure.

It has a lsx 454 cam, new lifters, and new headgaskets. Dod/afm deleted. And new oil sending unit.
I've narrowed it down to one of 3 things.
Oil pump (pressure relief valve)
Or the rubber orings that seal the lifter towers (didn't want to drill for plugs due to obvious reasons and can't afford the fancy pop rivet tool to plug them)
And to me, the less likely, bearings as it had good oil pressure before being pulled with the only variable being oil viscosity.

Any one have any ideas as to what is more probable or other probabilitys?

I had a similar issue with the 5.3 in my wife's tahoe after I did the dod/afm delete. I bought the ligenfelter dod plug kit and my oil pressure went back to normal. I just used it on my 2007 silverado when I did the dod/afm delete and oil pressure is steady at 40 at idle.

Wana rent the tool out? I can buy the plugs, it's the tool I don't want to pay $75 for and use once or twice over the years.

The L96 does not have DOD/AFM. 25lbs at idle seems normal once warm. 25-30 while cruising below 2000 rpms is also normal.

So if you did take out AFM components from that engine, it was not an L96, maybe an L76?

Is this the kit you got?
https://www.lingenfelter.com/product...l#.Wj2sq0xFzIU

It may not have dod/afm but it still has the lifter towers with the holes in them.
And 25 lbs is low enuff to make my oil light come on and my display read low oil pressure stop engine, altho I know it's not low enuff to hurt any thing it's just annoying seeing the lights on the dash.

Should be. That's the only kit I'm aware of. It's like $7X on summit. Pricy for a rivut gun. Wonder if the "rivet" plugs would work in a standard rivit gun?

That's exactly where I was going haha
Though the rivets do look pretty beefy

That's correct but you mentioned that the AFM/DOD was deleted.

Hmm... Doesn't sound right, has the computer thrown a code P0521?

My 17 is an L96 and it only makes about 25 psi hot idle... never goes over maybe 55 pounds but once hot its likely below 50. Seems to be normal and on par with most others. As accurate as the factory clusters and sending units are it might be worth checking otherwise.