What the guys are trying to explain is; that the numbers as far as what the factory provided, do all match up. But, those numbers are for the most part, only date codes. But, that being said is all that the factory provided for that particular car. I am pretty much in the same boat. I am 99% positive my car has the "born with" engine, can I absolutely prove it? NO! But I purchased my car in '86 and it had not been restored, it was a little rough and had been just sitting in an Apple Orchard for 3 or 4 years. Every # that I did find upon restoring the car and rebuilding the Engine matched. But again, we are only talking Date codes. (That is all that can be confirmed) I tell anybody that is interested that it is the original engine. Just my 2 c's.