Here is a picture of a 1953 - 235 block out of a passenger car with a powerglide. It was the first block produced with pressurized oiling. It has the side mount holes. There ae two up and one below, so it is a different pattern from a V-8.

1953 - 235 block with side mount bosses - driver side

1953 - 235 block with side mount bosses - passenger side