The cylinder head casting number is: 3835913

I can't find the block casting number, it isn't between the distributor and breather pipe hole and I don't see it anywhere else. The serial number stamped into the block next to the distributor is: 0392325F54Z

Wouldn't F54Z denote that is it as 1954 engine built at the Flint, MI plant?

1948 Chevy 3100 Thriftmaster pickup
Old skool engine swap ('54 pass 235)
Four on the floor
12v conversion