Hi,

Always rule out the ignition first as it’s the most vulnerable system.
Do not discount what is good or bad as there are environmental variations that can blow the whole thought of it.

Lots of connections if you count two ends of each wire attached to the distributor. That’s ten and only one need to be questionable a % one one cylinders power.

Then there the center contact onto the rotor button with a spring in between.
Add four more around the circle it’s makes.
It’s the middle man that can end up working through green smut on the caps terminals.

Then one should ohmmeter check each to have an even consistency of resistance on each wire.
Especially when connected onto a spark plug.
I check them all the way to the electrode itself as the plug boot hides the condition of the connection inside.

The spark plugs need the .028 gaps for the maximum results in the cylinders.

This is one third of the power plant that has only a fraction of a second to get things done right.

After clearing this system can you move on to an air or fuel delivery problem and how can it come and go crummy!

Phil