The block casting number comes back as a 58-62 235.
I think the date code comes back as August 3(?) 1958
I = August
3 = 3rd day of the month (but usually 2 digits)
8 = last digit of the year within the range of the block casting number.
Can't help on the block serial number. Maybe Flint plant produced Dec 16 for a truck
Here's the reference I used:
LINK
