Welcome to the Corvette Forums at the Corvette Action Center!

Spark Plugs


Well-known member
Feb 24, 2001
Camp Hill, PA
Formally Callaway SuperNatural Grand Sport #0001
I'm about to replace the plugs in my '96 SuperNatural.
I had been using Champions, which is what was originally installed by Callaway.

What brand is everyone else running or what do you suggest and what gap?

See everyone at Carlisle

When I pulled the plugs on my '95, I noticed that Callaway actually installed the WRONG type of plug for the LT1 motor. The plugs I found in the car were Champion RC9YC, which is a copper-based plug (which is better for performance), but with a washer (flat plug)...... LT1 motor's are supposed to be equipped with a tapered-end plug - no washer!! - my mechanic verified it with Callaway. I don't believe the Callaway-installed Champion's seal as well to the heads as tapered plugs.....if not sealed properly, you just might lose a tad of compression....

I have now installed NGK TR55 plugs in my car - copper, not platinum, and they are very well constructed plugs. You'll find many hi-po Vette owners are running NGK's.

Also, when I called Callaway, they said the gap should be set to 0.035, which is lower than the factory 0.050 setting. If you have an aftermarket ignition such as a MSD, stick with the wider opening, but if you have a stock ignition, try the lower setting.

Thanx for the info guys. The RC9YC's are what were installed in the car, however I have the LT4 engine so I don't know if that makes a difference.
I will look into the NKG's though.
I am running with the MSD 6AL ignition also
You have to understand something here Champion was sponcering Callaway so I would not be suprised to find Champion plugs they have been doing this ever since the 87TT. Also do worry to much about weather or not it has a tapered seat or washer what does matter is that if it has a tapered seat you can go with either but if it made for washer you can't use tapered seat plugs. If you don't believe me just check out the ZZ4 HO motor GM sells they give you 3 different plugs you can use some are tapered some are washers. I don't hampion so I would use something else I also don't like platnium, NGK wakes a good plug I also like AC rapit fire, but you do need to find the plug with the correct heat range and long threads.

David Fulcher

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Top Bottom