1963 FI Spark Plugs

[Rick A.]

Folks,

I know this topic has to have been discussed before but I sure as heck couldn't find anything in the archives. And in my 1975 Corvette Parts Catalogue there is NOTHING listed for the 1963 fuelie.

So, what was the original plugs used on the 1963 fuelie? And what would be a likely "modern" replacement?

[Dennis C.]

Re: 1963 FI Spark Plugs

Original plug, probably AC-44. Today, buy AC-R45. No need to complicate it beyond that. DC

[Duke W.]

Re: 1963 FI Spark Plugs

All early SBs regardless of HP rating used the AC44 as OE without any exceptions that I can think of, but it was a bit on the cold side for street and highway driving and the slightly hotter AC45 provided better service. AC no longer makes non-resistor plugs so the best substitute if you want to use AC is the R45 as Dennis said.

NGK and Denso still make a non-resistor plugs - the B4 and W14-U respectively that are equivalent heat range to the AC 45. Resistor plugs have been used on Corvette engines since about '68. The resistors are there to improve RFI performance. They dissipate a little energy, but should provide satisfactory service.

For race track hot lapping the AC 43 or equivalent is just about right. At high sustained engine output, a colder plug is required to keep the tip from overheating and causing preignition, which can lead to destructive detonation.

Duke

[Rick A.]

re: 1963 FI Spark Plugs - Dennis/Duke - THANKS! *NM*