VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1941 Block Stamping Mystery

I have been looking for a 41 block to help out a friend and have found one (I think) within a reasonable driving distance. The owner tells me the pad is stamped AAI09x1xx where the digit after the second A is the capital letter I rather than the number 1. I questioned if it was really the letter I rather than the number 1 and he said definitely the letter I since later in the sequence there is a number 1 and it doesn't resemble the third digit. Now the question. Was there ever a 41 engine stamped AAI prefix or could this be a stamping mistake by the factory? Other thoughts? Thanks, Mike

I find no 1941 engine numbers that begin with AA. Also Chevrolet did not use an "1" stamp but used an "I" instead.
What is the casting number?

From a previous post (#345308), I thought 1941 engine numbers ranged from AA-1001 through 1163729. It was my understanding there were also 1941 engines with an AC prefix. If the letter I was used as the number 1, then the third from last number is (AAI09x1xx) the anomaly. The block has the correct 839400 casting number.

My casting shows a i’s instead of 1’s and the original receipt shows 1’s
Am computer limited right now or I would show you. Sorry

Motor's Factory Shop Manual, Sixth edition, 4th printing, pg 250, 1941, Engine numbers begin with AA-1001 and up.

The capitol letter I was used instead of the numerical 1. A photo of my '38 engine number is below showing an "I" as the first number, 1.

Thanks for everyone's feedback. I should have looked at the engine in my 41 first, the third digit clearly shows as an "I". I'll have to wait until I see the engine that is for sale to determine why the seller tells me the third from last digit is a "1". Thanks again, Mike

Photos of my casting and original receipt. No ones...all "I"s, even though it shows ones on the receipt.

Wow.....look at the date.............not even 2 weeks after Pearl Harbor !!!!!

That would be od. Wonder if it was used or a demonstrator as 1941 prouction ended in August and 1942 began in Sept.

I know. My great grandmother drove the car thru 1965...odd that they traded in such a newish car. I’m told they were very frugal. I guess they saw the resource constraints coming.

What a great history on the car!

How many miles were showing when it went into retirement?

Thanks
Here is the longer history -> History
It got driven minimally after it was restored. Was appraised, post restoration, in 2008 with 77255. Came to me in mid 2018 with about 77900. I've added a little over 1000 in the 16 months I've had it.

Is it not true that 1941 engines built in Flint were numbered from AA1001 to AA1163729 and those built in Tonawonda numbered from AC1001 to AC195459? My '41 engine is clearly marked AC110078. Also, one can argue whether GM used a "1" or an "l." They used a sans serif font (a typeface without the little crossmarks (serifs) at the top and bottom of letters. All figures in the typeface are simply plain lines, in the case of the 1 and the l simply an up and down line. That might be an l, but it might also be a 1. At any rate, it clear that it is meant to be interpreted as a 1.

It a known fact that they used a capitoI I rather than the numeral 1. Your 1941 engine was made in about November of 1940 going by the number.
Also some numbers appear to be hand stamped and stamped one at a time.