Prefered Spark Plugs?
 

Just wondering what everyone prefers as far as spark plugs go.
Please note if they are N/A motors or Blown to help keep things straight.

Thanks
Mark

NGK 5673-8 in a blown application.

NGK BR6FS in the little Pachanga

AC Delco MR41T in N/A

I have been running A/C Rapid Fires in the Baja for years. I have had good luck with them. They are part #1

Mine had the NGK 5673-8 plugs in it when I bought it but they were a bit cold for the way i run. I switched to NGK UR5 plugs but I don't run the boat hard. By the way, we dyno'd the first engine with the UR5's and it made 681@5600 with 7 lbs. boost.
Mark, are you interested in trying my Thunderbolts with the V-6 modules? I'll even deliver them if you and Patti can take a break and go to the Oven Grinder for dinner.

NGK V7 N/A 502

NGK UR5's in my 525SC. They are the same heat range as an AC 41.

I had good luck with the Rapid Fire #1's in an n/a 454. Same heat range as an AC 43. They just don't make them cool enough for the 525SC.

What about Bosch plugs?

Thanks Guys, Just wanted to see what everyine was using I've used AC and Ngk's

Dave, The numbers look good on the dyno.!!!!
I got my motor back and it's ready to go back in the boat.
Just need to touch up some paint and polish the valve covers and intake.
I would like to try the V6 modules. I won't need them til summer.
Are you coming in for the COPs party on the 3rd?

Mark

Denso Irridiums. . .Expensive at $12 each but they are the best. BTW, Denso makes NGK's.

Chris

Stef's Performance