Spark plugs

[Morris R.]

Hello everyone,
what would be a good plug to put in a 66 corvette 327/350hp l79, trying to keep it stock as possible without giving up performance.
I was thinking ac 45. Thank you

[Philip P.]

Re: Spark plugs

Finding a non-resistor plug may be a pricy option. There is a set of AC44 on ebay $199.00.
AC R45 are available at most of the local parts places however.
Phil

[Morris R.]

Re: Spark plugs

Should i stay with a non resistor plug?

[Larry M.]

Re: Spark plugs

Morris:

If you want a really good set of vintage plugs, go on Ebay or the NCRS Driveline and get a set of AC 45 plugs. About $40 or so. They will last for years and years.

If you want something almost as good for about half the cost, buy a set of ACDELCO R45 plugs. They are still available. The archives also list other brands that are similar to the AC 45 and R45. Do a search for this information. It has been discussed MANY times.

Either one will work fine. The 43 and 44 heat range plugs are too cold for most of our typical around town driving. If folks are actually getting $199 for a box of AC 44 plugs, then I am sitting on a small gold mine in my garage. But I don't use the 44 in my cars anymore.....I use the 45.

Larry

[Duke W.]

Re: Spark plugs

Non-resistor versions of the out-of-production AC 45, the NGK B4 and Denso W14-U, cost about two bucks each.

Resistor vs. non-resistor for pre-'69 engines has been discussed many times. The bottom line is that it probably doesn't make much difference. There is not enough data to draw a conclusion, but theoretically a non-resistor plug will pass more energy to the electrode. The use of resistor plugs beginning in 1969 was to reduce RFI emissions.

The most important issue is to get the heat range right. All OE Corvette V-8s used for normal road driving should use AC heat range 5 or equivalent in another brand.

Duke