Needing reassurance on purchase

[Jacsey 70Z]

I think if this is not the original block they sure found a perfect block to put in. What I'm saying is the dates fit perfect for the car, and I think if you look on the oil filter flange it may make you feel better. I alway said a 70Z with the VIN on the pad is worth taking a second look at because i don't think it happened at the factory. But everyone thinks all correct engines should have it or else people will question the car, so they were added when they got a chance. Some did a better job then others, this guy did a lousy job like it was done in the car with the head on and free hand.
So like someone said you my have the original engine with a added VIN on the pad. If so I think you have a nice car with a lot of potential and a Great color and options you just paid to much.