Yenko block

[restorer]

Any information anyone could give me would be greatly appreciated, I have an opportunity to purchase a Yenko block with '69 aluminum heads and GM aluminum water pump. Does anyone know when they were produced, how many and average worth. Thanks Wes

[COPO]

The "074" ZL-1 / L-88 aluminum heads are not too difficult to find. I have seen a number of sets go for ~ $1,600 - $2,000 range in excellent condition. There is a set on EBAY right now that needs some welding repairs that could likely be purchased for under $500. There was a complete ZL-1 engine w/Yenko block at the Spring Carlisle show that was for sale at $10,000. I am not sure if it sold.

[JoeC]

I believe Chevy produced two different Alu. big block motor castings. One was the ZL1 with the 4.250 dia. cyl. bore. This ZL1 was then replaced with the œCan-Am” block with a 4.440 dia cyl. bore. The two blocks were similar but produced by different tooling because of the Cam-Am blocks siamese cyl. design. Chevy produced them until the early 70Ãs where they were used for various race applications.
In a 1984 magazine article covering the building of a 502 cu.in. drag race motor using the Yenko block, they describe the block as the Cam-am design with the 4.440 dia. Bore.
The article states that even in 1984 the block was hard to find but that Bill Smith from Yenko Performance and Marine intended to manufacture more of the blocks. I do not know if more were ever produced. I believe Bill Smith died around 1986.
In another article, where Bill Smith was interviewed, it states that Yenko acquired rights to produce the Alu. Block in 1976. Bill Smith said he bought Yenko Performance and Marine in 1981 from Don and was selling the Alu. Block and other GM high performance parts some with the Yenko name on them. Any of the PA. guys know more about Bill Smith and Yenko Performance and Marine? If Bill died in 1986 what happened to Yenko Performance and Marine? Did Don Yenko get involved again since he was alive for another year after this.