I was given a 455 short block a few weeks ago, had a little time to look it over earlier. It’s definitely a 455 with the ashtray pistons, large N crank, forgot to look if it was drilled for a manual.

Im ashamed to admit it, but I’m a little fuzzy on the vin decoding. The stamp on #1 cylinder just below the deck is:

30M37741

I do remember the 2nd digit is year (in this case 1970) the last 6 digits are the sequence numbers. What’s the first 3 and M stand for? If I remember correctly, one of those codes is what the engine was originally installed in.

Not that any of this really matters. It’s a standard bore 455 with a good crank. It turns freely, very little rust, and the price was right. They aren’t making them anymore, gotta grab them when you can.

 

3 Oldsmobile Division

0 1970

M Lansing, MI

 

Duh! Lansing=M!! I knew that.

I hang my head in shame.

 

I'm not sure, but I seem to recall that the first number of the 6-digit series (in the case of 37741?, it appears to be 3) might indicate the model series of the car the engine came from. Your 6-digit series is missing a digit.

Randy C.

 

Nope, sorry. The last six of the VIN derivative are the last six of the VIN, which is just the sequence number. The VIN derivative has no model info in it. The model and body style are positions 2-5 in the VIN and are not included in the VIN derivative.

 

Joe, wasn't there speculation at one point that the first of the last six digits might align with body style, at least loosely? I heard that 7XXXXX were likely Toronados,4,5, and 6 could have been B-Bodies. I have a 455 bought off Craigslist. The seller said it came out of a '68 Toro. It has the low intake manifold, and the VIN derivative begins with 38M7xxxxx. Just curios if there might be a kernel of truth hidden somewhere in the tribal knowledge.

 

Depending on the model year, Olds set aside blocks of numbers at the Lansing plant for certain model lines. For example, in the 1972 model year, Olds assigned A-body cars the sequence numbers 100001-400000. B/C-body cars got 400001-700000, and E-body cars got 700001-up. These blocks of assigned sequence numbers varied by year. Note the "Starting Serial Number" column on this 1972 VIN chart.

 

Thanks, Joe; I thought I remembered something along those lines. Thanks for posting the document!