There's a technical article (written by Ken Kaufmann and David Hayward) in the Technical Resources area of this website titled CHEVROLET CASTING NUMBERS 1924 TO 1928 that touches on this subject.

Here's a couple of sentences from that document:

Blocks were sourced from either Saginaw Products Company, Saginaw, Michigan [“S.P.C”] or Ferro Machine and Foundry Company, Cleveland, Ohio [“FERRO”]. Ferro had supplied Chevrolet with castings until Chevrolet Division took over the Saginaw Products Company plant in the Autumn/Fall of 1927 and renamed it the Chevrolet Gray Iron Foundry.

So, it would seem that all 1928 engine blocks came from the Chevrolet Gray Iron Foundry in Saginaw, Michigan.

The full document is located in the members-only Resources area of the VCCA's website. Having access to documents like this is just one of the many benefits of being a club member. 😉

If you are a club member and signed onto the website, this is how to find the document:

1. Go to the Resources pulldown menu, Click on FORMS - Downloadable,
2. Then click on Technical-Vehicle-Resources,
3. Then click on 1912-1928.
4. Look down the list of documents and the document is labeled 1924-1928-Chevrolet-Casting-Numbers.pdf. You can read it online or download it. If you download it, it is a PDF document so you'll need the Adobe Reader installed on your device in order to read it.

Cheers, Dean

@rustoholic Thank you for that info. I’ve got five 4cyl engines ( most in pieces ) that appear to be two different casting designs. Now I can track down which ones would be correct for a couple of 28 vehicles I’ve got.

An easy way to identify the year of the engine is to check the casting date of the engine. It is located in the middle of the block on the passenger side. The date has the following three components:

• The first component of the date is a letter that signifies the month the casting was made. A=Jan, B=Feb, etc.
• The second (middle)component is the day of the month it was cast. This will be a number between 1 and 31
• The last component of the date is a single number that indicates the year the casting was made. 0=1920, 1=1921, etc.

Cheers, Dean

So found out two engines are 1928, February and August. One is September 1926. Another is 1926 per the casting number but has a clockface type date indicator pointing at 5 o’clock.

The last engine is of the 1926 design, but can’t get to the numbers without moving a few hundred pounds of parts.