My new engine is just about finished, so I am trying to get everything I will need to get it together and installed in the car. I need help choosing a Spark plug brand and plug. The car is will run NA til the bugs are worked out and final NA tuning is done, however I have an 75-150 nitrous kit on the car as well. I want a plug that I can use for both if possible. Its a 355 w/ 11.7 compression ratio, worked LT1 castings, ported LT1 intake, full bolt ons, E/WP, Mallory 685 ignition, MSD coil. What would you recomend?

 

autolites 103's or the NGK iridium spark plugs.

 

ngk tr6's are good for high compression and especially boosted or sprayed motors.

 

AC Delco rapid fire. Take a look - http://www.acdelco.com/html/pi_plugs_rap_main.htm

Here's a write up from Wards autoworld - http://waw.wardsauto.com/ar/auto_gm_launches_new_3/

 

American made and no exotic metal in them.

 

I went with the ngk iridiums on my car and am happy with them.

 

So you recomend those Rapid fires then? What number.

 

RF14

 

AC Delco? haha... hahaha.

 

I'd do a search on those rapid fires and get a couple of other opinions... Personally, I'd never put another set in my LT1 (or any other engine for that matter).