PCM 16196396 Range selector 4L60E?

[Rob 689]

pretty common to see knock counts on startup and shutdown. tip-in knock counts could be timing related or fuel mixture. TBI heads don't need much all in timing they are an efficient chamber. 25-30* all in. Cruise will like mid-30s to low 40s, this is not your "regular" 36* all in SBC head, so try and not pay attention to too much you read on the internet...

What are the consequences of too far retarded ignition?

Aside from ridding it of knocks how do you know what it needs for peak power or at least as close to there as humanly possible without a dyno.