Re: ZL1 or Yenko Block?
 

The blue ZL1 sold new here in MN. Had a yenko replacement block in it around 1984.It was rebuilt by a local machine shop.The engine builder ground off the yenko crest and put in his own initials.This may have been a common practice in the past.Earl

Re: ZL1 or Yenko Block?
 

When Yenko purchased the rights to manufacture the ZL-1 engine from Chevrolet, They started with the GM castings. Winters notified Yenko that they could not use the Winters insignia on the blocks. Hence, the W in the snowflake was removed and the aluminum foundry stamped in their initials. Yenko stamped their alpha numeric inventory number in the timing chain area of the block. These blocks did not have an inventory or date cast on the side of the block. The Yenko blocks evolved in construction and appearance over time.

Re: ZL1 or Yenko Block?
 

Thanks Ed [img]/ubbthreads/images/graemlins/scholar.gif[/img] you told me that already i should have listen to you before [img]/ubbthreads/images/graemlins/blush.gif[/img] who is the foundry that made them for yenko? [img]/ubbthreads/images/graemlins/beers.gif[/img]

Re: ZL1 or Yenko Block?
 

I believe LaPorte Indiana LP

Re: ZL1 or Yenko Block?
 

Yenko was also working with a company outside of USA to make alu blocks for him.