wtf is going on? the ac delco part number that my dealership recommends is 41-974, the ac delco number that ls1.com sez will work is 41-906 and the plugs that i pulled out of my car ('99 z-28) have 41-952 on them!

now, i bought the car used, so i can easily believe that ones i pulled out of the car are not the right ones. however, what is with ls1.com recommending the wrong part number? or is it the right part number? surely the two spark plugs aren't the same thing are they? and if they are, why the difference in the numbers?

please help before i go outside and shoot myself...

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jay
san francisco

 

this one is easy...quit buying crap(ac delco) and go to your local auto parts store and ask for NGK TR55's...thats it!...no part numbers etc.
Rick

 

lol. thanks, but that is not exactly an answer to my question.

fwiw, i found out that the ac 41-952 is a recommended replacement plug for the stock 41-974 (according to the auto parts store). dunno about the 41-906, though. i will say this, the actual distance of from the end of the threads to to the tip of the electrode is quite different between those two- the 41-952 extends a good tenth of an inch deeper into the combustion chamber and there appears to be more electrode protruding from the insulator than the 41-906, as well.

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jay
san francisco

 

AC Delco isn't crap.They're just as good or better than the NGK's.Just don't buy the bottom-of-the-line AC Delco's and expect them to be as good.I have used the AC Delco Rapidfires for years and they work GREAT.Even with a 100hp shot on my old V6.Maybe that's where the different part #'s come in,they have different "types" of AC Delco plugs.
Kevin

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1998 Black Z28 A4
-------1/8-------
8.548 @ 83.64 MPH
Pics
Camaro/Firebird Birthday Bash

 

Its a good answer though, TR55s seem to work really well in these motors.....go get them.

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99 SS, Dark Metallic Blue, M6
SLP lid, KN, TBB, SLP Y-pipe, SLP loudmouth
ported MAFs, Nitto 315 DRs
Currently: 1/4 13.06@113.8 (gtech runs high in mph by about 4mph), 0-60 4.77 (w/passenger) Gtech'd
12.99@110.2, 2.06 60ft - Tazzo.
Also, 331 rwhp as measured on the Gtech

 

If I'm not mistaken, the 41-906 plug is the AC part # for the LT1 cars.