The item circled (above) is a block-off plate for cars without OSAC valve (which looks like part below). All it does reduces the rate of vacuum change to distributer vacuum advance – to reduce NOx emissions. Most people bypass it for better drivability (in states that allow that).
That block-off plate is hard to find and I’m sure someone would be willing to take it off your hands – if you elected to sell it . . .
The knock sensor needs to have a computer (Lean Burn, Spark Control Computer, or any of the other various names Chrysler has used) to control knocks/pings – which is one of the reasons to leave that system in place (especially if you use gasoline with varying levels of octane).
If you use a constant level of octane rating, then you can dispel that system (Lean Burn) altogether (which is N/A in your case) – with time spent on getting your ignition timing set properly.
Some of us, who use the low octane fuel for 90% of driving, then use the higher-octane fuel for racing – having a computer to control timing (and pinging) is a huge time saver.
Higher octane fuels can allow different spark timing – which in turn, helps engine run better. The cost of higher octane fuels is cost prohibitive for most driving.
Getting under hood to adjust distributer timing every other tank full – is a lot more time spent than I want to give . . .
In your case, ignition timing needs to be adjusted to eliminate the ping (or use higher octane fuel, which seams counterproductive with a /6).
If engine hadn’t been into recently, then a combustion chamber cleaning will help.
Keep in mind, every time you hear a “ping”, means the piston sustains damage as if you hit it with a ball-peen hammer, each and every time (ie: not good).
BudW