There should be a stamped (not cast) letter/number combination on a machined pad immediately behind the distributor. Decoding that information should give you a good indication of the original year of manufacture and the vehicle the engine came from.
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!