The Stovebolt Site Forums The Shop Area Engine Shop Strange engine serial number

I was trying to confirm the serial number of my engine. However, the first numbers don't look right. They look like they were hand stamped over the original numbers. Take a look at these photos.

I believe the 03 80 364 numbers at the beginning were hand stamped over the original serial number.

It looks like the original serial number was 022 (under 380) ? (under 3) 33 (under 64) and 9
This would make the serial number 022?339 but this would be a seven digit number and most serial numbers are six digits.

Any thoughts?

By the way, the model number F56TA indicates it was built in Flint in 1956 as a 6000 RPO 225. This engine is mounted on a 1955 2nd series 6400 2 ton truck. Would that mean that this was a replacement engine?


serial number photo 1

serial number photo 2

Looks to me like someone was having problems at the DMV?

The bigger digits underneath would be the original numbers.
The fist 6 digits are production numbers.
Meaning how many of that type of engine was built at the Flint, Michigan engine assembly plant.

The small digits on top of the original numbers are not something you would see on a GM replacement engine.

I was told that when a replacement engine was issued,
GM would send the mechanic a stamping die set to transfer the original engine serial numbers to the new replacement engine.
When done, the mechanic would send the stamping die set back to GM Headquarters.

In some states, DMV would use the engine serial numbers on the vehicle title, some used the vehicle serial number on the title.
You should check your title to see what number was used.
What ever is on the title it should match ether the ESN or VSN


F56TA - looks like original stamping
F - engine assembly plant, Flint, Michigan
56 - model year, 1956
TA- series & type designation, 6000 - RPO 225 HD heavy duty engine 261 cubic inch

You should check your other Block NUMBERS to verify what you have, you probably have 261 engine.
And to check block casting date.
Check here for 1956 Resto pack

My 1964 261 replacement engine is completely blank there. I would guess someone was trying to match a title to a truck.

If the original numbers are 022?339 does this look like a real serial number?

Ok-- here is the scoop on your engine 3837012 was a 216 built in 42-51 and someone was having fun playing with the serial-- the original serial is under side cover in the right lower corner surface --none there -- then it was a replacement --look behind the starter and the casting of letter --number --number such as
A 14 6 would be Jan 14 1946 last number is the year -- Beck's --

1956 was the last year for engine serial numbers. The engine serial numbering system in 1956 did use 7 didgits starting with 0001001.

So your original serial number 022?339 would be correct.

Mike B