Need plug recommendation.

Best Plug for Stock 85 for everyday driving & why?


Thanks
\dbaker

 

Hi.
I have an 85 4+3 z-51.
When I bought the car in 97 there were NGK plugs in. Don't know what specs but believe it should be the ones for an 85.
The car did not idle that perfect. I changed to AC Delco Rapidfire ( the ones for the stock cast iron heads) and the idle became much better. I could not say if I gained anything when driving though. I have used the rapidfires ever since and am very happy with them.

 

I will give my advise. It will likely start a huge debate. It does not really matter. I run ac-delco's in my 87. At 1 time they were .89 cent each. Your combustion chamber is filled with a volitle air fuel mixture. It doesn't car what spark makes it pop. Heat range , proper gap etc really matter. I have had problems with platinum, I have never had problems with a "normal" spark plug. I would rather change a cheap set of plugs ever year or 2 than put in a "good" set and have it last 10 years. Changing them often give you a good look at what is happening in the combustion chamber and keeps the threads from seizing up.

 

If it's stock, go with stock replacement.

The sparkplug argument has been going on for years, not worth the trouble.