3970010 blocks

[Brian J.]

Can anyone tell me if all the 3970010 blocks were cast with the same alloy, or were the earlier blocks the more desirable high nickel content?
Brian

[John H.]

Re: 3970010 blocks

About nine million 3970010 blocks were made over its 11-year run, and the additional tin/nickel alloying is cast into the front face of the block on the blocks poured that way. There's nothing "magic" about the "010/020" blocks - they got additional tin to improve machinability (longer tool life between changes) and additional nickel for a slightly harder finish-machined bore surface. Not a "big deal".

[John H.]

Re: 3970010 blocks - Addendum

As with most things Chevrolet, this got close scrutiny from the beanies, as the additional tin and nickel added product cost at the foundry level; when the promised overall cost reduction results didn't materialize (tool savings in the engine plants and long-term bore wear resulting in reduced warranty costs) enough to be identified, the more expensive "010/020" alloying quietly disappeared.

[Brian J.]

Thanks John *NM*