Can anybody help me with nickel contenet

I always thought if there was a 10 or a 20 under the timing chain cover it was 2% nickel and 1% tin but I just read something that has me confused.It says just what I stated obove and then continuse with if you have "either" 10 or 20 it has no tin but does contain 1 or 2% nickel.And still conitues to state that if there are no numbers under the timing chain cover it contains nothing. My numbers on my block under thr T/C cover are [COLOR="red"]778[/on the left side and[and [COLOR="red"]010[/on the right. and then the the numbers on the back are [COLOR="red"]3970010[/].
Sorry about all the words but I always thought I knew what I was talking about.
Thanks guys

This from Wikipedia,

"One of the biggest myths about the 307 is that all the blocks were cast with a very low nickel content. However, some 307 blocks, such as casting number 3970020 with suffix VxxxxTHA (x's in place for date), had 010 and 020 stamped under the timing chain cover indicating high tin and nickel content."

Kitz

Don't know about nickels, but I've had a lot of dollars in an engine!

Thanks folks, I'll be here all week!!!

What a sinister remark!:LOL:
I used to (had to ) help my uncle when I was 15 to 18 and he wouldn't use a motor(all 350's) if they didn't have that 010 or 020 on the right side of the cam bearing. And David Vizard speaks of it briefley in low budget high horse motors but now I'm kinda confuse from his statement. I don't know now.