DING DING DING SOUND THE ALARM!...

On the heads you just got? Why do they do that?
I got mine last year in September. I think I've seen up to 2017 last year on the Black Friday sale but 2020 by far is the newest I've seen. mind being 2015 when I took them in to have them check the only thing they really needed was some lubrication in the valve guides because they had kind of dried up from sitting on the shelf so long...