Spark plugs ??

[74Olds]

Hello all,

I am wondering about the plugs in my 455... I would like to change the plugs to the "correct' ones by using the info from the info sticker on the inside wheel well. It states that I should be looking for "AC R 46S" plugs, but I cannot find them anywhere. I was just curious to ask all who had a 455 what plugs you were running so that I could pick some up today or tomorrow... I had my parts store guy run the #'s for the plugs and he ordered me "platinum" plugs that came in on Monday, but I was advised not to go with the Platinum plugs for whatever reason...

Thanks,

[442MUCH]

Hello all,

I am wondering about the plugs in my 455... I would like to change the plugs to the "correct' ones by using the info from the info sticker on the inside wheel well. It states that I should be looking for "AC R 46S" plugs, but I cannot find them anywhere. I was just curious to ask all who had a 455 what plugs you were running so that I could pick some up today or tomorrow... I had my parts store guy run the #'s for the plugs and he ordered me "platinum" plugs that came in on Monday, but I was advised not to go with the Platinum plugs for whatever reason...

Thanks,

In my 455 (1976) I run AC Delco R45TS with an .080" gap.. I was also advised not to go with platinum. In my owners manual it says that I should use R46SX. Anyway, you should be able to find these at Canadian Tire, NAPA, Part Source etc.

[74Olds]

Excellent... Thanks for the info...

[442MUCH]

Here's something else I found:

In the GM catalog for the ZZ454/440 it states to use the #4 Rapid fire plug gaped at .045 for an HEI distributor.

The cross reference on this is:
25164642 - Rapid Fire #4, AC Delco #4, Covers R43XLS, R44XLS, R42XLS, R45XLS, 42XLS, R45XLS6, R44XLS6, 44XLS, 41-618.

25164643 - Rapid Fire #5, AC Delco #5, Covers FR3LS, FR3LS6, FR2LS, 41-603, FR3LSJ, FR4LSJ, FR5LS. Note: This plug will fit the ZZ4 crate engine.

25164644 - Rapid Fire #6, AC Delco #6, Covers R44LTSM, R44LTSM6, R45LTSM.

25171346 - Rapid Fire #7, AC Delco #7, Covers R46SX, R46SZ, R44S, R43S, R44SX, R46S, R45S, 45S, 46S.

25171347 - Rapid Fire #8, AC Delco #8, Covers R42LTS, R43LTS, R43LTS6, R42LTSM, R43LTSM, R42LTS6, MR43LTS.

25171348 - Rapid Fire #9, AC Delco #9, single plug. Covers FR1LS.

25171349 - Rapid Fire #10, AC Delco #10, Covers R44T, R44TX, R45T, R45TX, R43T, MR43T, MR43T, MR44T, R43T6, R46T6.

[74Olds]

I just thought about this before going to pick something up... I believe, in fact I'm positive that this car is still running with points... I'm thinking this may change the info slightly like gap size,, but will the plugs mentioned work with points as well...

thanks

[442MUCH]

I just thought about this before going to pick something up... I believe, in fact I'm positive that this car is still running with points... I'm thinking this may change the info slightly like gap size,, but will the plugs mentioned work with points as well...

thanks

Hmmm. Not sure. I can only tell you what it says for my 76 455.

[damaged442]

I'm running R45S in the 442 with the 350, gapped at .035. (with points)
I've got R46SZ gapped at .060 in my Cutlass with the 350 (HEI).

[74Olds]

Well, I got the 45TS plugs and threw a .042 gap at them and they are working out... We shall see after I add HEI in the spring about diff pugs and gap sizes... Now i just have to get my heat issues down... I don't know what to make of it, I thought the changing of plugs and gaps my assist with the heat thing, but not really. I have changed my rad to a 3 core I believe rad, I still have to find out more about those clutch fans, and I thought about changing the water pump to something better, but i am still going to high temps when I sit idle but do remain usually at the 1/4 on the rally pack gauge while driving...

I'm sure I'll figure it out sometime... OH also my floor right under my feet is terribly hot (the carpet has rotted and it's just the metal floor), I know the pipes are right there, so I may change out pipes for something else as the pipie I think are original, and although functional, the are red and rusted, so.....

Thanks for all the help btw :)

[73CS]

In my 455 (1976) I run AC Delco R45TS with an .080" gap.. I was also advised not to go with platinum. In my owners manual it says that I should use R46SX. Anyway, you should be able to find these at Canadian Tire, NAPA, Part Source etc.

Alright guys help me out, Why not run platinum? My 73 with 350 motor had sat for a lot of years before I purchased it, and there was a ton of carbon, soot and the like in the engine, gave it a tune up, cap, rotor, plugs, points and wires. I went through three sets of AC plugs while blowing the snot out of it (had carb issues also) I threw a set of Bosch 4036 plugs in and it Loves them. Changed the carb and changed to a HEI distributer, everything still works great. So why not platinum?? :confused:

[ragz442]

Alright guys help me out, Why not run platinum? My 73 with 350 motor had sat for a lot of years before I purchased it, and there was a ton of carbon, soot and the like in the engine, gave it a tune up, cap, rotor, plugs, points and wires. I went through three sets of AC plugs while blowing the snot out of it (had carb issues also) I threw a set of Bosch 4036 plugs in and it Loves them. Changed the carb and changed to a HEI distributer, everything still works great. So why not platinum?? :confused:

One thing I've found about plugs over the years, ask 10 different [qualified] people what to use, and you'll get 10 different answers. I say, If they work for ya, then go for it.

Me personally, I use A/C's in GM, Champions in Chryslers, Autolites in Fords etc..but I guess I'm kinda from the old school of thought.

[73CS]

I usually go for the AC also, and the Mopar and Ford guys can use whatever they want.

[ragz442]

I usually go for the AC also, and the Mopar and Ford guys can use whatever they want.

Well I've been a tech in Dodge stores since '92 and independent shops before that. Drive GM's, work on Chryslers :D . I know first hand, the 5.2-5.9's will flat out not run right with anything but Champions.

[73CS]

I know what you mean Ragz, I work in auto parts sales right now, and have been working on aircraft or wrenching on cars for over 25 years. Same thing with oil, ask ten people, get ten answers. I was just wondering if there is a technical reason for not using the platinums I had not heard of. (The Mopar, Ford comment was a joke, as I am a GM guy) That being said my brother in-law's 72 roadrunner with a 69 383 ran great with the cheap Bosch platinum plugs. I have also experienced certain vehicles that like a certain plug. If anyone has any info please chime in. Thanks.

Blane:)

[442MUCH]

Blane, my guess would be that the platinum plugs offer no noticable advantage but are more expensive. The may run better in imports but not V8's. I am no mechanic so this is just me thinking out loud.

[GT73]

GM used AC Delco spark plugs, the R stood for resistor, the number i.e. R45 meant the temperature of the plug. The lower the number, the cooler the temp. Therefore, friends who run Olds engines and use AC plugs often run the R44 plugs or you can use what is recommended for your car.

As for aftermarket plugs, platinum or iridium plugs are not necessary based on cost, they were never designed for our blocks. My buddy runs race cars and owns a part shop and recommended I run the NGK V Power plugs... http://www.ngksparkplugs.com/products/spark_plugs/vpower.asp

I agree with Ragz regarding the other brands, ex. Champion, Autolite, etc. they are not really geared towards GM cars. Run either the AC plugs or NGK V Power.