Hello, Doing research on what spark plugs are used in the 330 (High Comp) 4 barrel. I currently have the AC44S in the block. Nobody seems to sell these anymore. Auto part stores say to use the 43S. I have the 67 Service manual and I thought the heat ranges vs. Engine size chart was there, but can't find it. What type of plug do you guys use?
thanks Brian

 

When I had my 330 I used to use the Autolite 85

 

https://www.sparkplug-crossreference...t/AC_DELCO/44S

 

Here is the factory recommended spark plug for every Olds engine 1960 - 1969

http://www.carnut.com/specs/gen/olds60.html

43s did not come into play till 69

 

Autolite 85s will work fine.