Author Topic: Correct Spark Plugs for 1969 Z/28  (Read 849 times)

Edgemontvillage

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Correct Spark Plugs for 1969 Z/28
« on: April 03, 2017, 03:28:23 PM »
There has been much written on the the subject of spark plugs for a 1969 z/28.  The original AC 43R's are too cold and 45S are preferred by some (as are NGK, Autolite 86,Champion RJ14YC, and others) however which version of the R43's are born-with correct, the R43N with ACNITER script and 4 equal width green bands on the ceramic insulator

(eBay image) Delco R43N
Lloyd
1969 RS Z/28 (Brooklyn Project)

Boston14

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Re: Correct Spark Plugs for 1969 Z/28
« Reply #1 on: April 04, 2017, 12:26:16 AM »
I believe those are big block plugs.  The 'N' reach plugs will not seat the gaskets in small block heads.
boston14

1969 SS/RS 350 Convertible
Dover White with Black Top and D90 stripe, Red Standard Interior

Hans L

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Re: Correct Spark Plugs for 1969 Z/28
« Reply #2 on: April 07, 2017, 05:48:55 AM »
Lloyd -

After Jerry MacNeish's finished the engine rebuild for my Z, I asked what the factory installed - he said R43, no suffix (ie - no N or any letters after the 43).

There appear to be several styles available. 
- 1 thin green band on top
- 4 thin green bands
- 1 thick green band on top with three thin green bands

I have not been able to determine which is factory installed.  However, Charley Lillard's 1970 Z28 page, under engine, has a few pics of the original plugs and are the first style, 1 thin green band.   http://www.1970z28camaro.com/engine/    But this is for a 1970 Z28.   So not sure if these were also used in 1969 Z's.

For my Z, I sourced both R44 (Jerry recommends these for driving) and R43's in case I want to be technically correct.

Here's a few pics of the R43's:



http://www.littooy.com/hans/
'69 Camaro RS Z/28 Van Nuys Built
'69 Chevelle SS 396 4 Speed

68camaroz28

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Re: Correct Spark Plugs for 1969 Z/28
« Reply #3 on: April 07, 2017, 11:06:58 PM »
Not 100% sure Lloyd but I believe what Hans aforementioned is correct from what I've learned and thought for years, i.e. R43 4 equal bands. I believe the plugs with the 3 equal bands and one thicker band were later plugs and are not considered technically correct. Our 68 has 43 plugs with 4 equal bands.
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

Edgemontvillage

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Re: Correct Spark Plugs for 1969 Z/28
« Reply #4 on: April 10, 2017, 02:17:53 AM »
Thanks Hans & Chick.
Lloyd
1969 RS Z/28 (Brooklyn Project)

68camaroz28

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Re: Correct Spark Plugs for 1969 Z/28
« Reply #5 on: April 12, 2017, 02:03:52 AM »
Thanks Hans & Chick.
Lloyd, I checked my NCRS judging manuals and they do state the plugs should read acniter on porcelain. Note NCRS does not judge for correct spark plugs but do have information concerning correctness in their judging manuals as a "just to know."
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584