another question

1-does anyone know where to find the vin stamped into the rear housing on a 71 duster if they did that.
2-I have a part number off my piston from the 340 and was wondering if it is standard bore or not 2899479 is there any place to check this out
I'm only asking these questions because so far we have been lucky and everything is vin matching so far car, motor and trans.

Thanks