Can anyone help to brake down what these numbers on my engine block mean............FCSMHPO45571798........ As best as I can make out. I am trying to determine if the engine is original to the car. I am able to see it is correct for the year. Also the trans stamped number is 71M144358... that matches the vin number but what do these numbers on the trans tag mean....71-ow-4444. Are they supposed to match something? Any help would be appreciated I don't know to much about this stuff. Thanks

 

I can't help much on the first long number you posted. Its a funny coincidence that it contains 455 AND 71, your build year.


Here is where to look for the engine casting number: and by the way, this IS a 455 casting number. A 350 will have 395558 as the casing number.




Its good news you found the tranny vin derivitive number and it matches


71-ow-4444 this number is the model year (1971) OW is the user division, in this case, oldsmobile. The last 4 digits is the calibration code, its deals with internal specifications set at the factory.

Click on this link and be sure to look at any attachment links for pics, this will help you with the vin on the engine. It will show you the link (location)for the vin derivitive. In your case, its should be something like ? 3M1144358? The letter M means Lansing Michigan, which your tranny code has and the original block "should" also.

https://classicoldsmobile.com/forums...what-year.html

Oh, and welcome to the site

 

Thanks for the info. I was curious as to what the long number means. Fyi The long number came from the left front right below the head on the block. Hopefully someone will help me to decode it. Taking a Wild Guess is........... FCS ......unknown...M....Lansing......HPO....high performance....455.....engine.....71......year.... ....798....unknown.