There are different model hydra-matic transmissions that came from the different sizes of trucks. I suspect that your original bellhousing and torrus, along with the flywheel would bolt on to the front of the Pontiac transmission but could not say with any authority. Maybe someone who has been around more of the different manufacturer transmissions would know for sure. I would check with either restoratiohydramatics.com or areds.com. There are others also I am sure but that is a place to start.