There should be a stamped number on the top of the engine block just ahead of the passenger's side cylinder head. A 2 or 3 letter (not number) code at the end of the ID is used to decode the size and original application of the engine. I believe it can also identify the year of manufacture in some cases.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!