Nickel in blocks???

[iluv69s]

Saw this on FB.. varying replies as if it is an urban legend.

Anyone know the real deal?

[William]

One of the CRG Core members asked the same question years ago. The late John Z's response:

NOPE.

"Most people have no clue how a high-volume foundry operates - the "recipe" for the grey iron and malleable iron melt load wasn't changed; it was very carefully arrived at over the years, and its content was stabilized. The "high-nickel block" theory was debunked years ago, although some folks still cling to it."

John

[Too Many Projects]

Very interesting, I've always heard about the 010 block being high nickel too.
So, does anyone know what the 010, 020 509 indicate on a block ?

[RALLY]

Originally Posted by William

One of the CRG Core members asked the same question years ago. The late John Z's response:

NOPE.

"Most people have no clue how a high-volume foundry operates - the "recipe" for the grey iron and malleable iron melt load wasn't changed; it was very carefully arrived at over the years, and its content was stabilized. The "high-nickel block" theory was debunked years ago, although some folks still cling to it."

John

If anyone knew, it was the late great John Z. I asked him numerous questions about Chevy SB Heads and he always answered my emails.

[cheveslakr]

Last three digits of the part number, the block applies to 3 variants on this one.

[69 Post Sedan]

Originally Posted by jer

Last three digits of the part number, the block applies to 3 variants on this one.

This makes sense…..and what I assumed for years.

3970010
3970020
3951509

Kurt

[70 copo]

Well this can be tested. Get a 307 casting and drill into it and you will see how soft the casting is compared to the same year 010 302/350.

Start there.

Casting numbers are different due to changes in metallurgical content and design.

[70 copo]

Yep. and why the need for variants??

[70 copo]

Nearly all 010 castings from the mid 1970's onward were all "010" for all HP designations. Why were there basically no variants after hi compression was dropped?

[MarcDant]

Better yet just have a metal composition analysis preformed, it will tell you all you need to know about the high nickel block, after all they did cast the harder ductile main bearing caps. So the material was there.my .002 cents.