Tempest302

So I am looking at doing spark plugs but have some questions. Doing some googling it seems that the plugs differ between the aluminum and iron head l98. Mine is a 90 and so has an aluminum head. Someone said the stock plug was a AC Delco-r43ts. Summit racing site says that that does not work and it should be a AC Delco- R45TS. Anyone know which is right? Also, worth getting the rapid fire 5 platinum?

kael

Check the spark plugs listed on Rockauto, https://rockauto.com. They have pics of each plug, compare to the old. Note there are aluminum and cast iron listed, make sure they match.

ctmccloskey

The AC Delco Rapid Fire is a good spark plug as it worked well for my Corvettes. From what I have read the Old Delco R43 is no longer available and the R35 is the replacement for it.

THE most important thing is to use some anti-seize on the spark plugs that you install in the aluminum heads. Any time you are using a steel bolt into aluminum you should use anti-seize to prevent the aluminum from seizing the bolt from corrosion caused by dis-similar metals. If you do a bunch of plugs you might want to get the Champion Spark Plug Companies Special Anti-seize for their spark plugs. The Champion is a much thinner material and less messy but works really well. I keep both kinds in my roll about cart ready for action. I also have a tube of Die electric grease to seal the spark plug wires and make the boots easily removable.

Good Luck with your Spark plugs! Now think how much fun that would be on a mid engined Car like the C8, kind of makes me appreciate the old L98... At least I can still work on it.

Best regards,
Chris

Deepa

I think I’m running ngk fr4gp in my 91. No issues.

Tempest302

Thanks guys, went with the rapid fire 5s with summit racing cables. Now to google how to get to the plug behind the AC Compressor

PacerX

https://www.corvetteforum.com/forums...ion-check.html

Not even close to difficult.

Tempest302

Thanks, This helps a lot. Last person i asked said remove the AC compressor.