400 SBC hi nickel identification

[BrazilianZ28Camaro]

Hello friends

I just need some info about how to ID a hi-nickel 400ci factory block.

I've been reading different advises, so I'm confused.

There's a code or sign in the block to look for?

Hope the knowledgeable members here can shed some light

Thanks in advance!

[ProPower engines]

From what I have seen the 509 block has the rectangle bars cast in the valley meaning higher nickel content in the casting.
The blocks I have machined have had a shinier finished machined appearance and were slightly harder to hone.

There may me others with more nickel but a basic rule to go by is the 400 blocks had way more nickel to make them stronger because of there design.

[Jginger]

under the timing cover will be casting numbers cast in the block,
like 010 or 020 or both.

[BrazilianZ28Camaro]

Great info friends!

My 400ci #509 two bolt block have the rectangles in the lifter valley and "010" on the timing cover area.

Guess I'm lucky !!!