Nickel in blocks???

[70 copo]

The Story as we know it:

Nickel was used to harden the bore surfaces so the ring seal is better. Tin was used to make the block heat and cool more evenly. Tin and Nickel are shown as percentages in numbers cast into the block under the timing chain cover.

A "high nickel" block will have either "010" or "020", which indicates 10% and 20% nickel, accordingly.

The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel.

Some of the the early 400 SBC were also 010 and 020 cast and quickly became the go to choice for the circle track racers because they held up and dominated the track conditions the aftermarket followed and that motor became the go to engine for that kind of racing.