Spark plugs, misfires, and general ignition system

Good afternoon folks I’ve been getting a slight misfire at idle and at constant engine running speeds so today I decided to go ahead and pull the plugs and look under the rotor and see what was going on. The spark plugs all look about the same I’m posting a picture (#1 is on the right, #6 left) so any spark plug gurus can tell me if they look right or not, from what I can find online this seems to be a proper color. These plugs having about 400 miles on them total. When I pulled the cap, there is some arcing evidence near the five and three cylinder terminals, I’m wondering if whatever is causing this could be the reason for my misfire. I have ordered plug wires, and new plugs, just to remove those as a possibility of being an issue.

While looking for spark plugs, however I did observe that they make an HEI distributor that fits the engine, I am wondering if that would give me smoother ignition then I’m currently experiencing with the stock distributor, with an electronic module installed. 

I’ll pick up a new cap and rotor today and try that first.  

Thoughts on something like this?

Points, rotors, and caps are old technology. The ability to score good products has vastly reduced in the last couple of decades. Your problem may be as simple as a bad cap casting. Then again, it may not. Replacing the the cap and rotor may not help. Then again, it may. Do you see a theme developing?

Electronic ignition should not improve the running characteristics of a street driven points/condenser ignition. However, if the product quality is better, then it just might. There are good good conversion distributors and bad ones. To be honest, I don't know the status of the one in your link.

If you do go electronic, don't forget about the resistance wire which drops voltage to the coil. Electronic systems may require full 12V.

You might investigate Trader's suggestion of worn distributor bushings before dropping coin on electronic ignition. If you do the fix yourself, it will be cheaper.

The first car I ever drove had a 199 in it. It may not have an overabundance of power, but it took abuse from three teenagers and lived to tell the tale. Good solid engine IMO.

The ignition timing could be wrong as well. Over-advanced timing can cause an engine to stumble in a way that feels like a misfire. People often crank up the timing thinking more is better (not the case), so if you do not know what the timing is set at currently, I suggest checking it.