captras

I just purchased a 75 convertible...lookin to do a tune up...can anybody recommend a good plug...have read about the platinum plugs and the new iridium plugs and wondered if they make a diff in performance or economy.

Thanks

PureSilver

i just put platinum plugs in my truck, and the only reason it seemed to run better is that the old ones were pretty eroded. They were only about a dollar and a half more (each) than the stock type.

I think the wires and coil have as much to do with good spark as a plug does. Keep tuning it according to the schedule.

73'Vette

This might help ya some...

http://forums.corvetteforum.com/zerothread?id=731710

mvftw

I would NOT run platinums! Only if the engine called for it. They have a different heat range and after time may cause a miss. I would run AC Rapid fires or stock AC's.

stingraymaniac

ac delco. :thumbs:
works great !

munday

ac delcos, ngks...platinums are a waste of money, and if you are running dome pistons they can hit. Our boat had to have all the plugs indexed so they wouldn't hit.

Summerfun

Good plugs are NOT a waste of money.
It is a bit of a science though to get the right plug for a specific application
as there are quite a few things involved.
The right plug will give more efficient combustion, which leads to better fuel economy and more horsepower, be it only a few percent.

Any mods on a car should let you examine the setup closely so you can decide if you want to go with a hotter or colder plug than the stock recommendation. If you examine cheaper and more expensive plugs, you will notice different metals....which is related to different levels of conduction
and thus different degrees of heat of the flame as well as speed of the flame.

All this has an effect on the spread of combustion inside the chamber which is more pronounced in higher compression engines.

A more expensive plug will give you only a small percentage of benefit during the first couple of hundred miles, after that you will see increasing percentages of power and lower percentages of fuel consumption as time goes on......the extra dollar or so you pay for a better plug will pay for itself
over time and your pistons and valves will live in a better environment.... :auto:

.....my .02

JJ Deuce

double check on that. I know AC redesigned the rapid fires, and then I heard they've discontinued them.

BTW - friends in the parts business have told me that most of Delco's parts are outsourced these days - essentially what you'd get at O'reilly, Autozone, etc. in a red white and blue delco box. The Delco rep allegedly said they're not even making their own plugs anymore. :eek:

comp

:iagree: