55oval

Hello,

After installing fresh LS7 lifters in my LS6, I am getting what sounds like bad lifter knock from only 1 lifter. After startup and some driving w/ knock, I narrowed the noise down to the #1 cylinder (stethoscope). I tore the rockers out, nothing looks amiss, PRs look straight, rockers healthy.
**I measured preload w/ Dial indicator, and I have strange measurements from the #1 intake lifter. Please help me decide if I need to tear in deeper and zero in on that lifter.

Details:
Stock LS6, 60k miles. Ran just fine before these following mods all installed fresh just recently.
Boost Cam. Comp.
.614 .610 227 223 LSA 115
LS7 Lifters from Texas Speed
Comp Chromoly PRs 7.400
Dual springs etc.
Stock rocker assembly
LS9 Head Gaskets
Procomp Head Studs
Melling oil pump

I measured preload OVER AND OVER again with Dial indicator on most valves (because of difficulty mounting Dial indicator), saw consistent preload on all but the #1 intake.
I know the preload's a little high. I plan to go 7.375 PRs

#1: I-.75 E-1.05
#3: I-1.05 E-1.05
#5: I-na E-1.05
#7: I-1.05 E-na

#1 Intake rocker did have gummier threads than the rest. I torqued to 24, checked Preload, no change, tried 26, checked preload. No change.
Could this be a bad lifter out of the box?

Additional details:
Idle Oil PSI- 40
w/ gentle revs, Oil PSI sluggishly climbs to 60-70
w/ harder revs, Oil PSI responds a little quicker to 70+
Noise definitely quiets with more Oil PSI
Noise is inconsistent. It has nearly disappeared a couple of times, almost as something has settled down, but will reappear, even if just idling.
Yes, torqued to 22ft/lb, let lifters settle all the way.
Yes, dial indicator in line w/ PR
Yes, untorqued and D.I. would return to 0 (to double check that i didn't bump the D.I.)
I tried, but could not compress any of the lifters AT ALL by hand using a PR.

Any help is appreciated.
Thanks All!

Pic for fun. Not actually showing my measurement.

55oval

Bump? Should I post this in a different section?

slogo

Maybe try the internal section, you are in external engine. Good luck with the issue.

55oval

Thanks slogo; I didn't even notice! Derr.