340 Chugging instead of Reving

[1] Spark plug wire resistance is not the issue. I have a test where different wires with different ohms per foot resistance were used & the highest HP obtained was with wires that did NOT have the lowest resistance. The purpose of the test was to find out if wire res affected HP.
[2] You do not have to disconnect the dist to charge the battery.
[3] The pick up is obviously working because the engine runs; probably already stated earlier in the thread but air gap should be 0.008".
[4] Not aware of any reliable in-car test you can do on a p/up. They either work or they don't; long time use if VA is connected can break the wire[ s ] from flexing. Test with an ohmmeter, while flexing the wires. Reading should not change.
[5] Get the engine running & disconnect the alt wires. Then test drive. Test is to see if alt diodes are leaking/damaged & are producing AC ripple; transistors etc do not like AC.

It depends on which system he has in the distributor. If it’s a Unilite it needs to be unplugged.