Hi gang - let me reply to Douglas and Deke54 in the same message.
Douglas - I do have the data card, and know the original motor number, but it is not stamped on the block under the "250", near sparkplug 5/6. There was a flat spot for the engine number plate, and two holes to attach that plate as described by Merrill, but the plate is missing. One person that I have talked with said that I might have a dealer installed replacement engine, and that they were suppose to stamp the engine block with the number, or install the plate. Or, I had a plate, and it came off.
So I don't know if the engine I have is original, or a dealer installed one. If there was another place on the block that the engine number was stamped, I could solve this mystery!!
Deke54 - the plate is located under the raised letter on your engine block - under the "280" or in my case "250" near sparkplug numbers 5 & 6. I have attached a photo - but not from my car.
In this photo - it has both the stamped in number of the engine (look closely under the "250") and the number plate. I unfortuatelu have neither!!