Numbers matching

Thanks for all the leads. I found it!:cheers:
The engine numbers and letter is located back of the engine near the bell housing. As your standing in front of the car, it would be at the 12:00 position. Have to remove the oil sending unit to read. This is an engine number matches car vin. It has stamped (8B435180). The date of the block is on the driver side below the head.
It has stamped, 4-23-68. This car was special ordered in June of 1968. That makes it a late production car.The trans is from a 1972 car. The letter and numbers are stamped on a raised pad on the pass side of trans on a raised pad. It has the following, 2B256081.
It also has stamped, PP 635 3770 0391. Anybody know what this stands for?