So very stuck...

[1] Turning the dist CW retards ign timing. And vice versa.
[2] You are going off in all different directions....& getting nowhere.
[3] First thing to do is understand detonation. It is caused by heat, load & insufficient octane.


-load. It doesn't ping in neutral......because there is very little load on the engine. I will also bet that if you load the engine [ just as a quick test ] when cold it doesn't ping or if it does, only slightly.
- heat. Hypereutectic pistons. They require a very large top ring gap because the crown runs very hot. This is supposed to make more power because the combustion gas stays hotter, less pressure loss. But I often wonder if this makes the engine more detonation prone.
Lean mixture generates more heat, so avoid lean mixture.

[4] Make sure the engine cooling system is efficient. Make sure the rad cap maintains pressure. Make sure you use a t'stat 180 or 160. If the engine runs hot at idle, try a smaller w/pump pulley.
[5] Cold air induction. Not only does it give more hp, but it helps reduce detonation.
[6] Try richening the cruise cct of the carb.
[7] Only after you address the fundamentals above do you start playing with ign timing.
[8] It is mooooooooooost important to have the vac adv working. It should be connected to a manifold vac source [ NOT ported ]. Any port below the t/blades. You can tee into the brake booster port, any man vac port except the PCV line. Why is MVA so important compared to PVA? Because MVA adds timing at idle. PVA does not. The extra idle timing makes the engine more efficient, reduces running temp. If the engine has MVA & has been idling & you give it load, the engine is cooler as the instant the load is applied; it is less likely to detonate. You should have an adj vac unit [ large hex behind nipple ]. Adjust the Allen key fully CW.
[9] This type of engine will likely want about 30-32* of timing at idle. That can be ANY combination of initial + MVA. Since it has a propensity to detonate. I would use 8-10* init + the remainder from MVA [ example, 8* + 22* ]. Most adj VA units have a total of about 30* with the plunger fully deployed. You will need to fabricate a stop to limit travel to 22*. This is ALL part of tuning.
[9] You will need to experiment with the centri curve in the dist. Vac adv drops to zero under load. So if you used 8* init & you want 36* @ WOT, the internal curve needs to be 28*. If you have a GM type HEI dist [ excellent choice ], you can use the two inner holes on the cross bar [ that the rotor attaches too ] with a small nut & bolt to limit total travel. You may have to use stronger springs to delay the advance &/or grind the weights to achieve same.
[10] I doubt your bal has 'slipped'.