Still chasing false knock

[Paul Clark]

110 octane at only 17 lbs. of boost and still getting knock.
It only seems to happen from punching it at under 25 mph.
SC numbers are right on the mark.
My mechanic buddy (who knows Buicks) put it up on the hoist and couldn't find anything.
TC bolts are tight. Flywheel isn't cracked. Motor mounts are good. No clearance problems with anything.
Any ideas?
Maybe the wrong wax?
Thanks

 

[Quiky One]

Timing chain?

Jason