94flavette

Got my spark plugs from the Rock in the mail and they came in two packages and look like this...



What's the deal here? Will these still work together?? They are all the same part number.

WVZR-1

Another example of a very good reason to "buy local"!!

JackDidley

They will work in your 94. Clearly some have been on the shelf for a while and some are a new design.

94flavette

They were closeouts...these must have been the ones they found while cleaning out the warehouse...back in 1996.

PLRX

They are different. Why do you even need to ask?

leesvet

Hmmm...
IIWM, I'd want to install 8 that were alike. The thing I see, is the depth of the plugs reach into the chamber. That matters... There MIGHT only be a .3% difference in the flame path or combustion with a plug that drops 1mm further into the combustion chamber, BUT there is a difference. Besides, I'd be concerned about detonation/pre-ignition problems with more spark plug in the chamber than should be? Who knows which is the correct reach.. Unless one was meant to have a washer/seal and the other is not. That might level the reach of all.
Still, I like symmetry.

WVZR-1

The spark plug on the left is from ACD when ACD was not just a marketing brand and theoretically quality was controlled more stringently. The tooling for the product on the left was likely that of GM/ACD. The spark plug on the right is the offering from ACD presently and the source is ???

Eight of either is likely fine but I'd think a "mix" not.

gerardvg

The depth of the plugs in the head reaching into the chamber is a real concern, here in Australia Ford have sourced spark plugs locally and the thread was too long. Became a problem at the next service, the carbon build up on the threads made the removal damage the threads of the cylinder heads an expensive repair...

No wonder Ford is pulling out of manufacturing in Australia .....

Hope this spark plug issue doesn't happen to 94Flavette.

WVZR-1

All of the original "ribbed insulator" spark plugs with similar reach have maybe a 1 - 1.5mm shoulder at the base of the spark plug rather than "all thread" like the product on the right which is the problem you relate to in the FOMOCO offering down your way. It's quite obvious in the product on the left. I doubt there's a total length difference and that would need confirmed with a measuring device!

One might wonder which were the "close outs" - some of the smooth insulator/nickel plated ACD spark plugs seem to have the same thread considerations as those on the left.

JMelton

You would have been better off going to O'reilly, Autozone, Napa, or Advance to get the plugs, at least you could have verified they were all the same.

FWIW..... FSM for my 96 calls out AC 41-943 plugs, and I know for a fact that it will missfire with AC 14's installed.

C409

... Put 'em in ... the AC's on one side ... the AC/Delco's on the other ... then check to see if the car pulls harder on one side more than the other , then get back to us so we'll know which to buy ... .............

94flavette

I doubt I'll find the ones on the left - but they just look like a better quality plug.

WVZR-1

Might not be that difficult. Start with GM dealers and the part # 5614244 and then just ask them to pull them and check for the "ribbed" insulator. If they say yes then all you need to do is make the drive. The smaller the dealer the more likely you might be to find these. If they say yes we've got them don't assume that's correct, have them put there eye on them, their inventory system may just change the oldest part number to the newest.

5614244>19280524>19244465>19158032> are all possibles but the first will be the more likely.

A smaller auto parts store maybe also. A large ACD jobber not very likely.