Thread: 010,020 casting marks?

Tweet

Some blocks have a "010" above a "020" under the timing chain cover, I understand that to make the block more desirable over one without these casting marks, is that true? If so, Why?
I was told it represented 1%zinc and 2%nickle added to the block during the casting process.
Thanks,
LOST
Some blocks meaning Chevy small blocks.
Thanks

Lost- the high nickel content is what you want if you plan to twist the RPM's up.....although I guess you'd have to be in the John Force range to have to worry about that anymore as most cams won't allow you to get above 7k anymore.
I don't know anyone running any Chevy's on the street that can bust a block from twist that isn't sporting a blower.