[chevyman420]

does the 010 on the side of the block signify anything i've heard that it means four bolt but i'm not sure

[Jmark]

the 010 block is a very common block, usually a 350 2 bolt or 4 bolt. Only way to ck is to pull the pan and look.

[chevyman420]

so does the 010 mean anything

[techron]

NOPE......it just means you are looking at a chevy block--->

[chevyman420]

OK cool but if i remember correctly i think i read somewhere that it means that there is more nickle or something and that it's stronger?

[starnest]

Actually from some research I did on small blocks, the 010 cast into the side of the block signifies the percentage of nickel used in the iron for the casting. The 10% nickel content adds strength to the iron.

[chevyman420]

so it does mean something and it is stronger then because i think i got that from Mortec.com

[Double_v23]

That is just a myth, all blocks from that era had comparable amounts of nickel in them. Sometimed they put 010 on one side and 020 underneath it. So does it have 10 and 20 percent nickel? nope.

[xxllmm4]

I think the whole nickel tin thing is a big myth also. It supposedly means 010 is 1% nickel and 020 is 2% tin. Correct me if i'm wrong but If it was 10% nickel and 20% tin it would no longer be cast iron.

Jordon

[starnest]

Originally Posted by xxllmm4

I think the whole nickel tin thing is a big myth also. It supposedly means 010 is 1% nickel and 020 is 2% tin. Correct me if i'm wrong but If it was 10% nickel and 20% tin it would no longer be cast iron.

Jordon

Actually 10% was a typo, it is .010 or 1%. And I wasn't there, but from what I understand the earlier castings did not have any markings and the nickel content was negligible.
When high performance and heavy duty applications (early to mid 60s) caused blocks to fail, they started adding nickel to strengthen the blocks. By 1970 almost all blocks were cast with 1% nickel content, thus all of the blocks had 010 in the castings.
As for 020, my understanding is 2% nickel was used (I hadn't heard of using tin). I've never seen a block with 020 casting.
I can't recall where I read about this, and as always even if it's in writing, don't make it so.

[XNTRCI-T]

My block has both 010 and 020 on it. It is a '79 350 out of a truck, 4-bolt. I have heard the 1% nickel - 2% tin explanation many times, including from the racing engine shop that built my short block. I don't know for sure if it's true, but it does help me sleep better at night!

[DoubleVision]

Is the casting number 3970010? notice it ends in 010? this is common on these casting number blocks cause its part of the casting number. The past rumour of that 010 marking on the side indicates a 4 inch bore, but this has never been confirmed either as the true meaning, so it reflects back to what I just said, it means 3970010.

[XNTRCI-T]

Originally Posted by DoubleVision

Is the casting number 3970010? notice it ends in 010? this is common on these casting number blocks cause its part of the casting number. The past rumour of that 010 marking on the side indicates a 4 inch bore, but this has never been confirmed either as the true meaning, so it reflects back to what I just said, it means 3970010.

If you're asking me, yes the block casting number is 3970010. The 010 and 020 marks on my block are on the back of the block inside of the bolt circle for the bellhousing. I have a photo somewhere... I'll look for it.

[DoubleVision]

The marks on the rear or under the timing chain cover 010 and 020 represent the percentage of tin and nickel in the casting as mentioned, but on the side it means elsewise.

[glen242]

Originally Posted by DoubleVision

The marks on the rear or under the timing chain cover 010 and 020 represent the percentage of tin and nickel in the casting as mentioned, but on the side it means elsewise.

I thought the only place the tin, nickel numbers were found was under the timing cover. That was the only place my engine had them ('76 'vette).

You are correct as far as any numbers on the sides.