spark plugs for a 326ci V8

Freoway2 Posted 2012-11-09 3:30 AM (#346416) Subject: spark plugs for a 326ci V8 Member Posts: 49 Hi folks. I checked my plugs in my '59 Coronet 326 V8. They're NGK BP5S. In the original manual, they're quoted as being Motorcraft AR42, which is equivalent to an NGK BP5RS (or an NGK BPR5S-15). So the recommended plug has an "R" in it. In the NGK spec chart, it says "R" means special ground electrode. I'm not really sure what that's to do with. I'd perviously guessed that it hada something to do with running a coil with an external ballast resistor(?). Maybe that's wrong. I'm also running the regular Mopar electronic ignitino module with matching hall-effect distributor and ballast resistor like I've had on many Mopars before. Any thoughts? Cheers, Lloyd Shep Posted 2012-11-09 11:40 AM (#346459 - in reply to #346416) Subject: Re: spark plugs for a 326ci V8 Expert Posts: 3402 Location: Chestertown, NY ( near Lake George) I use a regular Autolite plug for that engine.