High-Nickel SBC Chevy blocks?

[ss wannabee]

Having an argument with a friend. I always thought that they were only available in the Chevy Performance Catalog...usually as a Bowtie block or something like that.

He says that some production-line blocks were high-nickel as well. Never heard of this...checked online...and the banter goes on and on...

Need the straight scoop..First WHAT is a high-nickel block? Isn't it really the percentage of (tin) in the cast-iron slurry at the foundry? Could the Bowtie or similar performance-catalog blocks have percentages of 10% or more?

Did regular cast blocks have a small percentage...(maybe 1, 2, or 3 %) anyway...and did GM adjust this... as needed...for production-line performance or Truck applications?

You machinists out there probably know...I hear these "hard" blocks are tough on cutting bits and stones....

[randy wilson]

Yes, there are high nickel content factory produced blocks. I believe they say 10 stamped on them somewhere. They'll correct me if I'm wrong. And possibly the 509 block. Someone else help out here.,

[Michael Kilduff]

I was thinking heat treating or cooling times/rates determines the hardness and that the '010' and '010/020' were different molds. But not sure. Discussed this in a Chemistry class with a grad student that was very familiar with metalurgy over 25 years ago.

[Tim H]

Not sure about high-nickel, but the front area behind timing cover used to to have numbers relating to nickel content in the old prodution blocks as I recall...

[Michael Kilduff]

Actually I'd be very suprised if GM used 'high nickel' in production blocks. I remember tearing down quite a few sbc's of 60's and 70's vintage out of crashed up cars in yards that had the 010 and 020 numbers in the castings...if that indeed correlated to high nickel content surely the cost to produce would be higher than using iron instead. Some of these blocks/engines were 307's and low performance 350 impalas and chevelles-4 door 2 barrel cars. No need to put expensive castings in those kinds of cars I would think.

[Tom Meyer]

If I remeber right chevy had a high nickle 4in block in the late 70s early 80s the number was in how to build a small block chevy book in that era I think I still have that book somewhere. My brother ordered one back in the day and never did anything with it. It was over 500$ back then. The 721 chevy II block from 1964 was also supost to be high nickle the 283 block that could be borded to 4 in. Tom

[Bob Lasko]

Originally Posted by randy wilson

Yes, there are high nickel content factory produced blocks. I believe they say 10 stamped on them somewhere. They'll correct me if I'm wrong. And possibly the 509 block. Someone else help out here.,

The older block had a 010 stamping.
Bob Lasko

[carl hinkson]

The 010 blocks or the K-cap blocks have poor webbing design over the 010/020 blocks.

Most 010/020 block have the 1/8 inch pipe plug above the timing cover and some these blocks had the 2482 nodular iron 4 bolt center caps.

Like any GM block if its going to be used in a performance application it should be sonic tested before any work or cleaning is done.

[Mike Semeniuk]

The 010 / 020 behind the timing cover blocks were the high nickel. Quite a few of them were in the 350 powered trucks - in Canada at least. The later versions had the oil galley tapped above the timing cover. Prior to these, the 509 blocks were the best and I believe from late 60's 327 and 350s. they were meater. kind of like the mid 60's 283 blocks with the deep oil filter pad. We used to have a wrecking yard and saw all versions of these over the years - but not as many as some would think. - or hope.

There are letters stamped on the oil pan rails by each cylinder that supposedly indicate how concentric the hole is. The 010/020 blocks had the least deviation of letters between the 8 cylinders - but then again, that may be an old wives tale.

[Greg Reimer 7376]

While going through some notes, I came across the 512 327 block. That's a service replacement block, cast after 1967. It's distinctive in that it has a screw on oil filter, like a 68 or newer SBC, and it is usually small journal.Tony Janes has one, and right next to the front cam bearing boss, are the numbers 010 020. They are kind of rare, but enough of them are out there that you should find one someplace.I also found out that some of those were large journal, so there is a starting place for a 350. Seems to me the 512 was intended to be a replacement for trucks, Corvettes, and performance applications.I guess it's pretty thick, as well.