Sounds like you have the Left bank in a good place. The valvetrain is accelerated and decelerated
at high speeds. And the sound of lifters tapping is the sound of parts hammering, pure and simple.
So the sound of quiet is when everything is set correctly, and you are making full use of the
clearance ramps on both sides of the cam lobe. (When there's excess clearance in your valve train it's pretty
much the same as when you drive your vehicle straight over a curb. Adjusted correctly to make use of
the clearance ramps, now it's like driving over the same curb with a wooden ramp in front of it -- so
much less shock stress over time.)
As for the lock nut questions. Most of the time the lock nuts will loosen up a bit, if anything.
But once in a great while I've had one start to tighten up & act as if it was going to seize on
me. On a couple of occasions I've replaced a problem lock nut. (See attached for a couple of
examples for the SBC.) I seem to remember a lock nut that didn't want to tighten, so I
brushed a little anti-seize on the stud, backed it off, wiped down the threads, and the new
nut went on with no problem. (The stud threads looked fine.)
Thanks to manufacturing tolerances, there's a bell curve for these lock nuts when it comes
to 'running torque'. (Resistance to turning.) In a set of 16, most are the same, one or two might
be a bit looser, and maybe 1 will be tighter. Luckily, replacements for out-of-spec lock nuts are readily
available and cheap. If that #2 intake nut is balky and making you nervous, maybe replace it and retry
the adjustment?
One last thing. That thread count of '5' is just a theoretical example, not necessarily a goal
or an ideal. If all 16 assemblies end up close to the same to each other, that is the real goal,
whether it's just 2 threads, 6 threads, or some value inbetween.
There's a lot of reasons why your thread count might be only a couple of threads, but the
point is that we just want them to be close to the same. (Remember, each thread is worth
~.060" worth of vertical travel at the lifter, so we just do the thread count as a mechanical
cross-check to verify I am getting this right.)
For what it's worth I've sorted out several new builds by others over the years that wouldn't
run smoothly (after verifying that the ignition & fueling were correct) by performing a running
preload adjustment. For whatever reason there would invariably be one of more lifters
bottomed out internally, and the builder would be surprised, thinking that they were all
set perfectly.
NOTE: When the preload was bottomed out, a compression test would be close but off a little,
but a leakdown test would then positively identify the misadjusted valve(s) via the hissing sound
out of the exhaust pipe or throttle body. (!) And then you would pull the valve cover and see
the suspect valve showing 1-2+ additional threads on the stud than the other valves.
****
Apologies for the long explanation, but at the same time it feels good to share these
valvetrain tricks with The Next Generation of GMT400 owners. I look forward to
seeing just how smooth & quiet you can get your old crate motor to operate.
Best of luck getting the right bank to match the left bank.
Cheers --
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