View Full Version : spark plug type

09-10-2010, 02:03 AM
i have 440-1 indy heads 15to 1 comp flat top pistons. i was wondering can i use a extended tip plug. i use ngk R5671A-9 was wanting to try a R5672 Series plug. Thanks

09-14-2010, 07:56 PM
No do not use extended type plug, I use RJ12YC Champion in mine :!: Extended tip might hit piston :!: JMO Mark

09-15-2010, 04:32 AM
thanks Mark . i should have said projected tip plug ? do you use the rj12yc in the Indy heads ?