Bo White

iTrader: (59)

I run AC plugs since I dont know when and will continue to do so so Im gonna get a set to put in now. Problem is the plugs I took out today are 41-931s and the gap is .067" and half of em dont have the platinum on em anymore. I am in the understanding these are the original plugs and the car has 119k miles on it. I checked with a local parts store and the replacements it calls for are 41-985s and just by lookin at em they are of a different heat range and so I dont want to try em. So I asked if they had any of the 931s and they told me its not a good # and sayed the 932s replaced em so I got those and they look just like my 931s(which they should) but they are gapped .060" right out of the box . Anyone know/remember what the 98 cars had in em from GM? Does anyone know the heat range of the AC plugs like a chart of some sort? Thanx in advance BTW, I want to keep runnin AC's
Also the 985s were gapped .037" or so out of the box(which was what they said it took stock replacement).

SouthernSilverSpeed

iTrader: (2)

From the factory they had the 931's. I just changed mine like 3 days ago and they were factory. You need to put in the 985's as they are working just fine in my car no problems!!

p.s. I work at a parts store and trust me I know that the 985's are right!

Bo White

iTrader: (59)

Thanx SSS! The only thing is the tune on it is good(thanx again gomer!) that I dont want to deviate(?) from it parts wise- except the LS6 springs(thanx redtail2426) and 7.400 Comp PRs I installed today . I borrowed the Crane VS tool from TA TECH(thanx again) and let me tell ya everyone need one of these in their toolbox

SLPSS01

iTrader: (6)

I'm also running the 41-985 iridium plugs since last year with no problems. They come pre-gapped at .040 and it says not to deviate from this so that is how they went in my car. Best price I found on these was from GM Parts Direct a set of 8 for $39.20 ($4.90 ea) Part No 12571164 They were double that at the dealer and local parts stores.
I replaced the original plugs that came in my car Denso PTJ16R15 (12563707) gapped at .060 with NGK TR55 before going to the 41-985's, didn't care for them. I couldn't find the Denso part number anywhere. My car is an 01 so I'm not sure the 98's got the same ?

MARKSZ71

iTrader: (3)

hey bo if u ever need any ac delco parts let me know i can hook u up from work

Bo White

iTrader: (59)

Thanx fellas(and Ill talk at ya soon Mark). Ive been doin a little research and the 985s are gapped smaller to make up the difference in heat range difference between the 931s- so Ive been told anyway. Im gonna run the 985s I guess and grab me some Taylor wires and do the swap the morning I go to the dyno again. Thanx again

blkbird

iTrader: (28)

My car came with denso plugs....

TAwhore

mine came wish bosch they are shot to ****, the nodes are all burnt off

replaced mine with del co's

i put 7 of 8 plugs in, and i already noticed a huge differnce in idle, power, and MPG!

jdoyle

iTrader: (27)

how many miles are we supposed to get out of these plugs? 100k?

how many miles are you guys getting out these 41-985s?

anyone making it to 100k?

01SS99red

iTrader: (6)

Just put some NGK TR55 and you'll be fine. Set of 8 is a little over $20 bucks

Bo White

iTrader: (59)

Agreed, TR55s all the way. Thats what I put in mine later on.

69LT1Bird

iTrader: (1)

....and you all do know that AC Delco does not make their own spark plugs, right. They could be Bosch, Denso or any other low bidder, just so you know.

The Ac Delco spark plug plant here in lovely Flint Michigan is a big empty field.

jdoyle

iTrader: (27)

NGK TR55s at .055" gap it is!