What spark plugs?

[sam79]

Hi all,

I've got kind of stupid question I think. Could one of you tell me what type of spark plugs I've to use in a 68-76 Chevy block casting number 3970014? This engine is in my brothers Chevy van and I do not know which type of spark plugs I need. I can't find the right type of engine in the Haynes manual and the old spark plugs do not have any number on them so that I can identify them. I hope you can help!

[swervin ervin]

From what I could tell, it depends. Like a 72 uses AC R44T. Then a 76 could use either a R44T or R45TS. I think it depends on whether it came with a EGR valve or something.

[sam79]

Mike,

I'm not sure. The previous owner replaced the old engine for this one and the are a lot of los wire and stuff. Where should I like for the EGR-valve? And is there a big difference between the 2 types of plugs?

Thanks in advance