Old Spark plugs and boxes

[Mike E.]

Note the dates on the ends of the boxes. I'm assuming these plugs are from 1970 or 1971. Are they correctly configured for a 71-72 big block? And how do you interpret the month on the box with only 4 through 12?
Thanks!P2210321.jpgP2210323.jpgP2210325.jpgP2210326.jpgP2210327.jpg

[Terry M.]

Re: Old Spark plugs and boxes

Note the dates on the ends of the boxes. I'm assuming these plugs are from 1970 or 1971. Are they correctly configured for a 71-72 big block? And how do you interpret the month on the box with only 4 through 12?
Thanks![ATTACH=CONFIG]58737[/ATTACH][ATTACH=CONFIG]58738[/ATTACH][ATTACH=CONFIG]58739[/ATTACH][ATTACH=CONFIG]58740[/ATTACH][ATTACH=CONFIG]58741[/ATTACH]

Month is 3 = March 11970 in first picture. Second picture is 11 = November 1970

The will work for 1970 LS-5 also.

[Joe L.]

Re: Old Spark plugs and boxes

Note the dates on the ends of the boxes. I'm assuming these plugs are from 1970 or 1971. Are they correctly configured for a 71-72 big block? And how do you interpret the month on the box with only 4 through 12?
Thanks![ATTACH=CONFIG]58737[/ATTACH][ATTACH=CONFIG]58738[/ATTACH][ATTACH=CONFIG]58739[/ATTACH][ATTACH=CONFIG]58740[/ATTACH][ATTACH=CONFIG]58741[/ATTACH]

Mike------


1971-72 big blocks were originally equipped with R43T. The R43TS (i.e. extended tip) was not originally used for these applications. However, they can be used.

[Mike E.]

Re: Old Spark plugs and boxes

Joe,
I have an original owners manual from 1970 that indicates R43T. My original 71 manual says R43TS. Original 72 manual doesn't indicate anything.

[Joe L.]

Re: Old Spark plugs and boxes

Joe,
I have an original owners manual from 1970 that indicates R43T. My original 71 manual says R43TS. Original 72 manual doesn't indicate anything.

Mike------

Yes, I see what happened: I didn't check back far enough. The 1971 LS-5 used the AC R43TS, GM #5613325. However, the 5613325 was discontinued in March, 1973 and replaced by GM #5613354, the AC R43T. That's why I found the plug to be the R43T.

However, as far as I can tell, the original plug for 1972 LS-5 was the AC R44T, GM #5613355.