[Lee H]

There will be lots of debate on this for sure. 60-70s Chevy "car" blocks like you mentioned had a vin derivative and a engine output code stamped on the front pad. Those engines can be traced to only one car and a numbers matching engine in a corvette, camaro, etc adds 10-15-20k or more to value VS an non numbers matching engine. All blocks have a date code that will correspond closely with the build date of the vehicle. All these things need to align with a build sheet and vin tag in order to be numbers matching.

A block can easily be decoded, write done the casting number, date code, and front pad data and we can help you decode it, or you can find a website to assist with decoding.

As Coley said, truck blocks did not have vin stampings so you could find a block with the correct casting number, dated code, and front pad stamp, and call it matching numbers. At this point in time I don't think truck values are much different with or without a "numbers matching" engine.