AC Delco Rapid Fire Spark Plugs
#2
I don't know the difference between the #1 and #2, but the RF #1 is a cross ref with the MR43T.
I ran them in an engine a long time ago. It was a little rich at idle and the RF's helped and did not foul out.
I ran them in an engine a long time ago. It was a little rich at idle and the RF's helped and did not foul out.
#5
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Joined: Oct 2005
Posts: 1,899
Likes: 20
From: Millstadt, IL
Yea, I agree. After searching many auto parts stores I found a set of new old stock #1's. ACDelco has changed the design and lowed the quality of the new product. Same part number but a completly different plug.
#6
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Joined: Sep 2007
Posts: 532
Likes: 1
From: Lapeer, MI
#7
You could also try some AC R43TS plugs. Thye have a slightly extended tip.




