Timing vs AFR which wins

here is a video that that shows you lean AFR is only good for bring on detonation. rich AFR just counteracts detonation. Timing is everything, if you increase time to detonation point and then richen the AFR up and little to stop the detonation then do it, and then increase the timing a little more until detonation returns and then back off a couple of degrees of timing for safety.

this is a must watch video to dispel a few myths about tuning.

https://www.youtube.com/watch?v=HXX4zcPr9IE&t=924s