View Full Version : SPARK PLUGS for 1979, Olds 350

bird 60
08-24-2016, 02:18 AM
Hi Guys, I'm assuming someone else has a 1979 Cadillac Eldorado with the 350ci Oldsmobile Engine. The recommended Spark Plugs in my Manual are AC R-47 SX. What is the equivalent NGK plug? I've had the Eldo for 2 years now & I thought I'd change plugs. The ones in the car are NGK B6E S., but I don't know if they are the right ones.
If someone can help it would be gratefully appreciated.

Thank You.

Chris.......From OZ.

08-24-2016, 09:05 AM
The AC Delco catalog shows a R46SZ, not an R47SX. I can't even find that plug listed. The NGK equivalent would be a 4536.


bird 60
08-25-2016, 04:15 AM
Thanks John. My Cadillac Manual definitely states AC R-47 SX.
Looks like the AC R-46 SZ has superseded the original from back in '79. No wonder I couldn't cross reference. Everything is A OK
now. I still can't get over the 60 thou gap.

Thank you.
Chris....From OZ.