cadillac 331 block number 1456291

[wkristick]

Anyone know the year of this engine?

[Jay Friedman]

I believe that number 1456291 is a casting number, which I am not familiar with

However, there should be an engine serial number or VIN number on a boss at the front of the right (passenger's) bank of cylinders, just in front of the bottom of the right cylinder head.  The first 2 digits of this number denote the year. 

Also, there should be a "unit number" on a flat spot at the back of the motor on the top of the left side of the flywheel housing.  This number consists of a single digit number, followed by one or more letters, then a number with one or more digits.  If you provide this number I can look up the year.

[LEADDIN]

Hello, I just started doing research on a 331 I have for a project of mine. my numbers on the front boss of the block are 506119376. The numbers on the top of the flywheel housing are 8(or 3) by itself below that 1456291 below that 3-29. I found on the drivers side of the flywheel housing 13. 8M201 is on the boss on the left side of the flywheel housing. Thanks for any help

[Jay Friedman]

506119376 (50 61 19376) means the motor was in a 1950 Series 61 and was the 19376th Cadillac produced in 1950. 

8M201.   The M is a code for 1950 motors.  The 8 is a code for motors in Series 61 cars with a standard (manual) transmission.  The 201 means it was the 201st motor built for a 1950 Series 61 with a standard transmission.

So, even though it was the 19376th Cadillac produced in 1950, only 201 of those was a Series 61 with a standard transmission. 

[Roger Zimmermann]

Anyone know the year of this engine?

This casting number was for engines used from 1949 to 1953. As Jay wrote, you have to search for the stamped numbers for an exact year.