I think everyone is avoiding your Delco electronic ignition advance question knowing they wiil be 99% wrong not knowing the specifics of your actual installed system.
Your best information on spark timing modifications would be someone regional to you having done this already for conversion to propane fuels and/or racing with your actual Delco system.
Here if the Delco electronic is a Distributor type system then a cable arraignment is made up to from the operators position hand turn and lock in place the actual distributor body. This is OK for the earlier systems still having built into the distributor centrifugal mechnical and vacumn pot chamber advance systems still mounted in/on the actual distributor.
Still with a distributor system: but now with these timing change controls done remotely by a computor procesoor then still the same cable distributor turning arrangement with now a disconnct swtich put into the computor to the distributor “command” wire (usually pink colored here).
Delco distributor-less systems here with now only multiple coil pacs most here find they need to do nothing and the systems will advance on their own as controlled by a pezio electric engine installed knock sensor.
Some of these earlier Delco Electronics CCC (Computor Command and Control) styles could be hacked controled by a pre-programmed computor chip replacement. Then that possiblty was eliminated. Then some can force more timing advance by activly “tweaking” with either the air flow or barometric/manifold pressure sensors to computor imputs. These “tweeker” (current cultural spelling now) sensor simulator boxes are Internet available. ALL Depends on the actual individual system.
Or, find the crankshaft sensor position. Bracket build and put on a second advanced sensor. Switch between the two as needed. Due to space, clearances and rotating moving parts it would be hard to make this two sensor timing “hack” variably adjustable like turning a distributor body.
Still lots of depends, depends, depends. Most of our late model vehicle electronic systems after ~2003-05 will detect this as a fault and force into a limited reduced power “limp-in” running until the “fault” is corrected and the computor then reset.
If you are talking a vehicle application with a manual transmission then a gear shift mounted timing change switch might have to be used to momentary allow the increased advance prior to the gear change.
Please have a good English language knowledgeable working auto technician translate this as needed.