"Appears factory to me" NOT! If it was factory it would have 2 bolt mains. I downloaded the picture of the bottom side and then blew it up. It's plain to see it's a 2 bolt. It doesn't look like the splash pan is bolted down and could be removed for pictures. Also the vin #'s coincide with assembly date but the 'O' in 'MO' looks funny.The only thing factory 68 Z/28 on this motor is 'possibly the block/crank' and intake, the heads, pistons, carburetor, valve covers etc are NOT! So it comes down to this, its this a legit 68 Z/28 MO 302 BLOCK?