Anyone know what year Chevelle went from the large plug to the small plug?

I believe that was 1970. Someone can correct me if I'm wrong. I have a '69 now with the large plugs and used to have a 1970 that had the small plugs.

Thanks, I appreciate it.

Basically, I think that's correct. I'm not sure, but in late production 69, when they went to the 402 engine (3 letter suffix codes), those could have been the start of the 'peanut plugs'.