You might get a dozen different spins on your last set of questions. Be here is the deal on spark plugs. If ones you have work with your current set up, leave them alone. Unless of coarse they are used up and require the regular maintenance change out. Double plats last like 50K, just leave them. If a spark plug works, it works. Granted copper plugs have some advantages, but so do plats. The performance is the same, except in rare occasions one type or another might prevent a problem. Maybe. For example you want to know about that AL 605 plug which is one step colder, well unless you drive like a maniac cold plugs won’t help you at all. But what you might get is less mpg.
And spark plug gap, use the standard gap. A smaller gap just compensates for a problem somewhere else. Basically you always to run the biggest gap you can, a small gap can hurt your engine performance. The gap spec is .060", and it is the same for N/A engines.
Basically you are working your self into frenzy over nothing, believe it or not these cars were design well. If you don’t mess with them, they last for ever.
