30 degrees advance on a high static compression ratio LA 360 “might be” slightly high unless your cam lowers the dynamic compression. Plain old carbon deposits in just one cylinder can cause the pinging.

If it is any help here is a full throttle run recording of a Magnum 5.9 V8 on 89 Octane (actually 89 antiknock index) gasoline. Magnum heads swirl and tumble the air more so they require less spark advance than at least some of the LA cylinder heads.

the information below came from a full throttle run on a 1995 Magnum 5.9V8 Ram pickup:
******
I have been playing around with the 'record' feature of the Actron ScanTool
with OBD-I Chrysler Cartridge on my 1995 5.9V8 auto with 3.21 differential
gears.

This records and stores 5 readings, 3 seconds apart, of what happened with the
PCM computer sensors before you hit the button, and an additional 10 readings
3 seconds apart afterwards

Here is what the ScanTool recorded on some runs at full throttle in 2nd gear
up a pretty steep hill { I guess about 4% grade)
Outside temperature was in the 70's and the barometric pressure was 29.6 inches Hg.

MPH....RPM....SparkAdv..Vacuum....O2 voltsDC

40......2804.......19..........0.9..........0.86
48......3175.......19..........1.1..........0.90
54......3485.......18..........1.2..........0.90
60......3787.......21..........1.5..........0.90
65......4093.......24..........1.6..........0.90
71......4471.......24..........1.7..........0.92
76......4785.......28..........1.7..........0.90
80......5040.......28..........1.8..........0.90

Comments:
(a) I can't explain why the degrees of advance went down from 19 to 18 around
3400 rpm, but it read the same on two runs. Notice this occurs near the engine
Torque peak, where cylinder pressures are highest.

(b) note that the NTK made O2 sensor stays fairly rich at 0.90 volts.
14.7 air/fuel mixture is at 0.40 to 0.50 volts, so that reading confirms rich mixture.
By design full throttle stock Magnum 5.9 V8 air to fuel is a very rich 11.8

1995 FSM says 5.2 and 5.9 V8 static compression ratio is 9.1
Later year 1998 Dodge advertising dropped 5.9 V8 SCR to 8.9
With the 13 cc dish pistons typically 0.050 in the hole “real world” static might be around 8.7