[iluv69s]

It sounds like a work order number...actually could be a machine shop work order number. The first set of alum heads I had worked on the machime shop stamped 1/4" 6 digit and 1 letter numbesr in the front of each head. It was thier work order number. I almost died when I picked up the heads.

I owned a ML stamped ZL-1 block with no VIN. One of the vette motors that never got used.

I thought i hit the jackpot when I realized it had the code for the vette. Although it had no VIN, I figured it had to be one of two.
After a few days and some research I realized what I had.