How true. And there's a lot of the 6.2's at or above 200k that are running between 15 and say 23 at a hot idle in gear with bearings in good condition. I'm inclined to think it's more related to the lifter bores, and it being an aluminum block with more expansion. I think it would be accurate to say that any 6.2 over 200k should benefit from a higher pressure/volume oil pump.
And what's the official GM spec on it? Something crazy, like 6 PSI per thousand RPM? I guess I'm biased by old school thinking, I remember seeing the incredibly low spec and I personally just can't accept that.
there's an inspecter at my work that has a older chevy truck with the 4.8. I heard it across the parking lot tapping away, I walked over thinking afm, but I didn't know it was a 4.8 at the time, they never got afm, I say man those lifters aren't going to make it home. he's like nah, it's been like this for years. he got the truck for free from someone, decided to drive it till it stopped but never has. he reved it up, the oil pressure came up and it stopped tapping. idled for a while, and started tapping again.
kinda amazing he's driven it on that forever and it doesn't seem to care. sounds like there's not enough pressure to pump up the lifter at idle.
if you're just daily driving these things around town and you don't have a hard tapping noise. I wouldn't worry about it. that low spec is probably actually fine.. it's something like 6psi at 1000rpm hot. not even a min as the 600 or less rpm these things idle at.
funny thou, my hybrid 6.0 is exactly the same inside as any other ls engine, but they put a different pump on it and min spec is like 30 at 1000rpm and I've never seen it under 40 running even with 170k on it. I got no clue why thou. that's more than a gear style high volume pump would get you.