I've been crawling under my car looking for the VIN number stamping on my '74 Z28 Muncie M21. I found the build code P4M20B, but not the VIN.

Thanks.

On my 73 Z28 the vin # is on the passenger side right above the build code if I remember correctly. Maybe below the build code. I'll go check if that would help.
Phil

Pass side between the drain plug and the speedo drove. It's stamped vertically on a pad where main case and tail housing bolt together. If it was a replacement trans (warranty) it will not have a VIN

There's a bit of road grime on it - I'll clean the areas suggested and find it. Its the original transmission so I'm sure it'll be there.