Spark Plug question.....

[Glennster]

Is a Bosch Platinum 4018 OK for a 340?

[Strawdawg]

I have never tried platinum plugs in a mopar, but, I have found they detonate quicker in other performance cars when pushed hard.

YMMV.

[Chryco Psycho]

in a dyno test we did years ago we found that the more expensive the plug the more power we lost , the Autolite & Champion made the most power , the more exotic the plug the more power was lost

[the_engineers]

So E3's are out?

[moper]

I've never had good luck with Bosch platinums in an old engine. I use NGK race plugs in race engines, but pretty much everything else gets Autolites because I found they withstood the multi-spark ignitions better than Champion. Not more power. Just lasted better.