Small Block Chevy Stamp decode [Archive] - Team Camaro Tech

: Small Block Chevy Stamp decode

May 7th, 05, 07:42 PM
I have a stamp on the pad of the engine in my 69. I know it is not the original engine, but would like to know what it is. I may not have all of the info here but here is what I can see. CE9B20558 any ideas. I think there should be another 3 letter stamp after that???

May 7th, 05, 09:16 PM
This is a GM warranty block and could very well be the documented block for your car. This does not imply that it is the original but rather a GM authorized replacement under warranty. The CE prefix represents a block replaced under the 5/50 warranty. The B is seen occasionally and its relevance is unknown. The final numbers represent the sequential number this block falls within the total number of GM replacements. If the installing GM dealer followed procedure a vin # will be stamped on the rough casting near the oil filter.


May 8th, 05, 06:47 AM
I beleive the B means that there were more blocks produced than the original allottment of serial numbers for that plant. So B is the second or third (Can't recall if A was used) time around for the serial number that followed. In other words, lots of demand for replacement engines. High failure rate??

Note-These serial number not only included engines but also partial engines, fitted block etc. So it does not necessarily mean a complete engine was used. Original engine parts were often reused when in good condition. Things like heads, intake, oil pan, rocker covers, timing covers etc would be reused.

CE - Chevrolet Engine (warranty)
9 - Model year produced for
B - Serial number prefix
20558 - Flint Engine plant built this, they used serial number range 20000 to 49999

May 8th, 05, 09:22 AM
Great information. One other question. Is there any way to tell the year of the block so I know the appropriate replacment intake manifold etc. This may have been a GM replacement block from some other car all together. The guy I bought the car from said he had the engine rebuilt, but he bought the car in 1985 and I don't know what year he had it rebuilt or if this was the same engine in the car when he bought it. I was planning on changing the current intake which the numbers indicate it is off of an 81 Corvette. Planning to use an Edelbrock Performance intake but they have 2 different intakes depending on the year of the engine. Any ideas? Thanks

May 8th, 05, 09:36 AM

These should help you find all the codes on the block.

May 8th, 05, 02:48 PM
The decoding mystery continues. Got the block casting number, 3970010, which says that code code be a 302 69 Z28 or 69-80 350 with 2 or 4 bolt main. I was unable to see the date code. Will have to move some stuff to see it. Someone mentioned a possible number that might be stamped by the oil filter. Specifically, where would that be stamped? That might help. It would be sweet if this was a 302 69 z28 engine. Thanks

May 9th, 05, 06:34 AM
3970010 is casting in use for 10 yrs.(69-79), so millions were cast. Chances its a 302 are slim to none.

You are not going to find a CON VIN stamped on a replacement engine. But if it were, it would be on the rear engine flange, up from oil filter, stamped vertically...

May 10th, 05, 07:29 AM
Just for conversation sake I would like to add that warranty replacement blocks were still under warranty by GM for the remainder of the initial purchase gaurantee period. The authorized GM dealers were supposed to document the block with the corresponding vin # by using the same conventional gang stamp as the factory would use. It was not always done of course and at times relocated to other areas of the block and can be very light and undetectable under paint. I found mine on the verticle rough casting near the filter only after being hot tanked. Only the number 4 was visible through the paint. I had been looking for information on the letter suffix code, I have seen "A" used before, and it certainly makes sense that it would be a repeat of the series for the plant sequential numbering system as the warranty sequence encompassed blocks for all GM models produced there. I would also be interested if anyone has information about the year code being for the model year or year of replacement? I know some GM documentation is recorded stating "model year" however I have seen CE blocks with vin# and year of replacement in the sequence. It's conceivable that some confusion of procedure may have taken place at the service end.