Educate me please !!! LA info needed

1Badcolt said
Ok thank you
This is a 72 model block
I have a 68 - 70 - (2) 74 model blocks all trucks blocks like this one and none have this machining so was just curious.

Yea they used multiple tools at once to bore, Also they started around that time with like a sizing tool in cutter heads so they need clearance