Have you checked the voltage at the coil while it’s running?
Checked voltage on the hot side of the resistor, and compared that vs the voltage at the battery?

Many years ago on my heap, I put in a higher rpm motor than I had run previously, which allowed some ign issuers to show up.

In my case I had lots of loss through the old factory wiring.
I peeled off some of the insulation in several spots and it was all green inside.

That’s when I went to a MSD 6A box...... since the power feed wires go direct to the battery, bypassing all the factory wiring........ and getting rid of the ballast.
I used the big yellow Accel Super Coil with it, which was already used when I got the car in 1981.

That being said, in my mind, it’s just as likely a valvetrain issue as ignition.

The pitfalls of fast rate hyd cams:
https://www.hotrod.com/articles/mopp-0510-440-engine-dyno-test/