[grahambehan]

Good Morning,
It is an interesting question which the simple answer to is yes a stock LT5 will show some Knock retard in low MAP partial throttle operation, also so on some transient throttle/load conditions, but should not when at full load conditions.
So this begs a few of questions
Why?
The knock sensor and control system are from the 80’s.
The LT5 is a relatively mechanically noisy engine.
Spark transition from light load advance to higher load is, in today’s terms, relatively slow thereby giving to mush spark under some transient throttle conditions.
With a single knock sensor some cylinders combustion events are “seen” better than others leading to compromises to the criteria of “what constitutes a detonation event in a well seen cylinder to a less seen cylinder.
Is it real knock ?
Simple answer yes and no
There may be detonation events through throttle/load transitions
Since cylinders combustion events vary in the amount they vibrate the block at the knock sensor position and all cylinders require monitoring to the best of the systems abilities, a normal combustion event is a cylinder that is “seen” better by the sensor, in terms of block excitation, may be interpreted as detonation.
Is it harmful ?
In most cases no
There are instances, in terms of temp and load where the spark retard is limited, e.g. on L98 cals of the day knock retard authority was set at 0 up to 50 kpa vac.

Why does it change ?
The LT5 calibrations have a rudimentary form of Low octane spark modifiers which are primarily based on coolant temp with modifiers for load and rpm.
Any change in the internal structure of the engine can change the resonant frequency of the system, thereby changing what is interpreted as a detonation event.
Piston and cam changes can effect this signature too.
Hope this helps
Graham