Need help determine cause of missfire

So I was able to do a little more testing tonight and I have some information pertaining to my missfire issue.
I’ve determined that this is not a missfire that’s limited to just one cylinder... this is a missfire that’s affecting all 8 cylinders.
I hooked the timing light up to every cylinder and brought the rpm up to 2500 rpm where it starts missing and I could see the break in the light on every cylinder.
I put a plug into cylinder 8s wire and started it and I did have spark while idling.
I didn’t want to bring the rpms up to 2500 with the plug on the valve cover but at idle it is getting spark.
So after discovering this I called an old mechanic I know who is a Ford Guy but has some experience with Mopar’s and explained the problem and explained everything I’ve done to try and solve the problem and he said based on the fact that this issue was happening with your previous distributor and now you have the same problem with your new distributor and that you’ve tried a new coil to no avail and you’ve tried new plug wires that you have ohmed and your pick up coil is testing within spec he said I think it’s your crane ignition box.
Thoughts?