AC DELCO Plug help!! # please

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Oct 27, 2025 | 07:48 AM

#21

the blur

Melting Slicks

Joined: Apr 2004

Posts: 2,764

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From: cyberspace NY

Quote:

Originally Posted by IHBD

You have the part number wrong.

R43TS is the standard duty taper seat plug used for many, many decades. It still exists on RockAuto for $1.66 each.

There is also a CR43TS. Same plug, but the leading "C" is a "commercial" application with a larger diameter center electrode. Everything else is the same as the R43TS. Rock Auto has CR43TS for the same $1.66 each. I've used both with no discernable difference, I change copper core plugs at about 35,000 mile intervals..

In the late 80's, there was a plug R43CTS. & R45CTS. Not a leading C. But where I have it in the part #.

Oct 27, 2025 | 10:42 AM

#22

IHBD

Melting Slicks

Joined: Nov 2016

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From: So Cal

2023 C4 of the Year Finalist - Unmodified

Quote:

Originally Posted by the blur

In the late 80's, there was a plug R43CTS. & R45CTS. Not a leading C. But where I have it in the part #.

There may have been. If there was, the trailing "C" was copper core. I thought all "regular" delco plugs are copper core now. Maybe they are, and that is why the suffix C was dropped? Doesn't matter to me, the plug numbers I cited work for me. They will for you too. You're welcome.

Last edited by IHBD; Oct 27, 2025 at 11:36 AM.

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