Matching Numbers

[jaybirdk5]

Tried looking at past posts and still have not come up with definite answer regarding matching numbers.Some posts I have read say the factory did not stamp matching numbers on engine block. Is that true? I have a 69 Blazer being restored and the numbers on the block are a manufactured 69 block but do not match. I have read in posts the correct number would be stamped on protecto plate but mine was not included with the blazer when I purchased it. The blazer seemed to be all original except for the rally wheels. Any input would be appreciated!

[Mike C]

They did. My own opinion, who cares when it comes to the trucks.

http://www.nastyz28.com/chevy-engine-code-stampings.php

[DeadheadNM]

I thought GM stopped stamping VINs on the engines of passenger cars after 1968. Not sure pickups ever had these stamped - at least by 1972 they did not.

[jaybirdk5]

A couple posts stated the factory was not as critical with the trucks. One post stated the trucks had installed whatever was in front of them during assembly as long as the displacement matched . Does not make much sense to me.

[jaybirdk5]

Thank you for the info.

[joea307]

I have a engine code on the upper front right side of my engine,what my protecto plate tells me is the same engine number,haven't found some of the other numbers yet,i belive numbers matching means something to whoever the owner is,for me my blazer is the only 1972,cst ochre,4spd,single wall top and a/c blazer in the country,if anyone else finds one that would be cool,but other than that doesn't make it worth more.

[IronCanine]

Mike C's link is a good one. Dollars to doughnuts, that's your original block if it's date code correct. Most likely only has the engine casting and engine ID #s. When I was on the hunt for a date code correct block for my Blazer, there were a couple of suffixes that I think could have been considered correct. For verification you can correlate your engine ID (plant/date/type) with the driver's door build date decal, to ensure the engine date precedes the truck build date. If your block has a VIN and it doesn't match the SPID, well...then it's not the original...but likely the only VINs on the truck are on the drivers' side frame rail, the SPID, VIN plate in the jam, build date decal on driver's door (if still there), any documentation you may have.

As complete and original as your truck appeared, I believe it's the original block...so my opinion is...If the block doesn't have a stamped VIN, and the engine date codes before your truck build date, and your frame VIN and VIN plate match...feel confident in calling it a numbers matching truck.

...if your blue door decal is gone, other useful date codes for individual assemblies may be found on the transfer case, bucket seat foam, back of the gauge cluster, under the dash pad, under the carpet, the seat belts, and the rear axle.