ZL-1 stamping numbers

[GMH454]

Date is 1969 can't remember the actual but I think its Febuary. Will dig it out from the back of the garage on the weekend.
The numbers I was referring to were 107.
This is stamped in the Aluminium up near the top edge of the block in the lifter valley area. I think the back of the block.
What surprised me however was the bottom end caps were also stamped with the same number (using the same stamp) caps are steel and are also stamped with a sequence number. 1,2,3, etc. They were covered with surface rust and I did'nt really think they belonged with the engine but I was cleaning them up as I was sick of geting rust dust on my hands everytime I move them.
I can understand a race team may number the caps but would they number them in sequence with a block number
Engine pad stamping is1-8880-61-A, which is numerically in line with race engines supplied in around 1971.