Can anyone help me identify the age of this block by the stamped numbers. I'm sure it's a Mexican SBF 302 block from the engine casting reference, but I cannot find any conclusive reference to the engine stamping numbers
I don't know too much about these blocks but here is the info that I have.
Look for HECHO EN MEXICO in the lifter valley.
Identified by casting numbers C8AM-B, 75ZY-AA, D1ZM-AA, etc.
Contrary to the myths these blocks do not have a higher nickel content but they have beefier main caps and webs probably because the cast iron used was less good than good old USA stuff. May be be stronger as they were not the thin wall casting type.
I had a quick look at my copy of How To Rebuild Small Block Ford Engines By Tom Monroe and did not see those numbers in the chart . If you look that book up I think a free download can be found , it has a lot of casting numbers and rebuild info .
As far as I can make out the mexican blocks used an initial number instead of a letter for the engine date code. So the 75ZY-AA would be a 1975 block. The rest of the letters I would guess refer to the vehicle it was for. Most of the mexican blocks went into trucks etc.
Casting numbers C8AM-B, C8AZ-B, 75ZY-AA, D1ZM-AA, these blocks have "Hecho En Mexico" or just plain MEXICO cast in the lifter valley. An extra non machined boss protruding from the front of the driver's side cylinder bank can be easily spotted in the form of a couple of humps that aren't on the US blocks.
They also used the 289 Hi Po style main bearing caps .
My machinist told me that the reason the Mexican blocks exists was that a certain amount of the parts, including engine parts, on vehicles sold in Mexico had to be made there by law. So they cast the blocks there, and they made the mains and caps a little thicker not for extra strength, but because they used a lower grade of iron (iron ore from Mexican mines, also a government requirement) so they had to make them thicker to get the same strength as the American version. He's built several, and says they are the same strength as regular 302s but no stronger.
Hope this helps.