Firstgens.com

I purchased a GM crate engine, 350 cubic inches with 300 hp, for my '69. I'm running electronic ignition. Any suggestions for what spark plugs I should run in it. I'm looking for brand and type.

Thanks.

first things first, you need to verify the physical sizw plug you need. Most likely, that crate motor will have "late model" type heads. You should be able to see if you look in the holes.

60's style heads use a short plug with a flat seat and a gasket on the plug, such as an AC R44s

When I got "good heads" they used late model "peanut plugs" These plugs have a longer reach, smaller 5/8 hex, and a tapered seat (45 degree, no gasket) A plug used on an LT1 90's corvette works here, such as an R44ts

Here's a chart of AC spark plug coding http://www.acdelco.com/parts/spark-plug ... cation.jsp

Well that's weird... I'm on my wifes PC, but swear I logged in with my user ID?

ok, that's better