figuring out advance timing

If your idle timing was optimized you might find that the engine likes 25/35 degrees at idle. If you set it there, with a typical stall convertor, the engine will bang the trans hard on engagement. The cure is to take timing out until it stops clanging the trans, and jumping the chassis.
The first time that Power-Timing is important is at stall.
and the second time is around 3500 rpm. So get that window figured out first. Then ramp the Stall timing DOWN, to whatever makes the trans happy at idle.
BTW
On my 11/1 carb'd 367 with alloy heads, she was no faster/quicker, on the Go-Pro SS with Power-Timing at 36, versus 32; so I run in the window of 32>34. and, She liked up to 60* of cruise timing with one combo I had. But with the current combo, all I give her is up to 54*@3400 or so, which with 3.55s and in direct (manual-trans), works out to 77 mph. However, at 65=2240 in overdrive, this drops to 48*typical, and 54*max with the dash-mounted, dial-back, timing module. These settings gets me max fuel economy.
My timing curve is linear from ~1000 to ~2800, when it hits the second spring that slows it down to all-in at ~3400. By delaying that last little bit, I can run 87E10 full-time without detonation.
My vacuum advance rolls in 22 Degrees as quickly as possible, which is all I could get out of her. A member here @TrailBeast got 24* out of his. This might help you. By setting your All-in to 34, and adding up to 24 or more for cruising, you can get at least 58*. If too much or not enough, only you will be able to determine.