Despite searching Google and here I couldn't find much discussion/recommendation on spark plugs for a mildly built 4.2 with headers and 45 DCOE webers. Looking for high performance street application and to avoid plug fouling. Using a standard gold ignition coil.

On a related topic, anyone notice an improvement with Webers and an upgraded coil or MSD?

 

Show us a picture - always ran N11Y in mine many years ago



Show us a picture - always ran N11Y in mine many years ago

 

Good information in this post Best/correct spark plugs XJ6 4.2 (1974) I have used the NKG BP5EY in mild tune XKE and XJ6 EFI, both with Pertronix electronics
Rgds
David

 

Thank you. I have the NGK now, BP5 I believe. Heard good things about the NGK in general. Would they be right for a 300 hp motor I wonder?

 

Just want to say that is a pretty motor!